Apex Controller:

public class SampleAuraController {
    
    //Get Contact List
    @AuraEnabled
    public static List<Contact> getContactList(Integer recordLimit, Integer recordOffset){
        Integer intLimit = Integer.valueof(recordLimit);
        Integer intOffset = Integer.valueof(recordOffset);
        List<Contact> conList = new List<Contact>();
        conList = [SELECT Id, Name, Email, Phone FROM Contact LIMIT :intLimit Offset :intOffset];
        return conList;
    }
    
    //Get Total Number of Contacts
    @AuraEnabled
    public static Integer getTotalContacts(){
        AggregateResult results = [SELECT Count(Id) TotalContacts  From Contact];
        Integer totalContacts = (Integer)results.get('TotalContacts') ; 
        return totalContacts;
    } 
    
    //Delete Contact
    @AuraEnabled
    public static void deleteContact(Contact con){
        Delete con;
    } 
}

Lightning Component:

<!--Sample.cmp--> 
<aura:component controller="SampleAuraController" implements="flexipage:availableForAllPageTypes,force:appHostable">
    
    <!--Declare Attributes-->
    <aura:attribute name="data" type="Object"/>
    <aura:attribute name="columns" type="List"/>
    <aura:attribute name="selectedRowsCount" type="Integer" default="0"/>
    <aura:attribute name="selectedRowsDetails" type="Object" />
    <aura:attribute name="selectedRowsList" type="List" />
    <aura:attribute name="maxRowSelection" type="Integer" default="10"/>
    <aura:attribute name="selectedRows" type="List" />
    <aura:attribute name="enableInfiniteLoading" type="Boolean" default="true"/>
    <aura:attribute name="initialRows" type="Integer" default="10"/>
    <aura:attribute name="rowsToLoad" type="Integer" default="10"/>
    <aura:attribute name="totalNumberOfRows" type="Integer" default="10"/>
    <aura:attribute name="loadMoreStatus" type="String" default="Please scroll down to load more data"/>
    <aura:attribute name="showRowNumberColumn" type="Boolean" default="false"/>
    <aura:attribute name="rowNumberOffset" type="Integer" default="0"/>
    <aura:attribute name="rowsToAdd" type="Integer" default="10"/>
    <aura:attribute name="currentCount" type="Integer" default="10"/>
    <aura:attribute name="sortedBy" type="String"/>
    <aura:attribute name="sortedDirection" type="String"/>
    <aura:attribute name="defaultSortDirection" type="String"/>
    
    <!--Declare Handlers-->
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
    
    <!--Component Start-->
    <div class="slds-m-around_xx-large" style="height: 300px">
        <lightning:datatable columns="{!v.columns}"
                             data="{!v.data}"
                             keyField="Id"
                             showRowNumberColumn="true"
                             rowNumberOffset="0"
                             onrowaction="{!c.handleRowAction}"
                             selectedRows="{!v.selectedRows}"
                             maxRowSelection="{!v.maxRowSelection}"
                             onrowselection="{!c.handleSelectedRow}"
                             enableInfiniteLoading="true"
                             loadMoreOffset="{!v.loadMoreOffset}"
                             sortedBy="{!v.sortedBy}"
                             sortedDirection="{!v.sortedDirection}"
                             defaultSortDirection="{!v.defaultSortDirection }"
                             onsort="{!c.handleColumnSorting}"
                             onloadmore="{!c.handleLoadMoreContacts}"/>
        <br/>
        <div class="slds-float_left">
            <strong>Total Rows : {!v.totalNumberOfRows}</strong>
            &nbsp;&nbsp;
            <strong>Selected Rows: {!v.selectedRowsCount }</strong>
        </div>
        <div class="slds-float_right">
            <strong>{!v.loadMoreStatus}</strong>
        </div>
        <br/>
        <br/>
        <div class="slds-float_left">
            <lightning:button label="Get Selected Contacts"  variant="brand" onclick="{!c.handleSelectedRows}"/>    
        </div>
    </div>
    <!--Component End-->
</aura:component>

Lightning Component JS Controller:

({
    doInit : function(component, event, helper) {
        helper.getTotalNumberOfContacts(component);
        helper.getColumnAndAction(component);
        helper.getContacts(component);
    },
    
    handleLoadMoreContacts: function (component, event, helper) {
        event.getSource().set("v.isLoading", true);
        component.set('v.loadMoreStatus', 'Loading....');
        helper.getMoreContacts(component, component.get('v.rowsToLoad')).then($A.getCallback(function (data) {
            if (component.get('v.data').length == component.get('v.totalNumberOfRows')) {
                component.set('v.enableInfiniteLoading', false);
                component.set('v.loadMoreStatus', 'No more data to load');
            } else {
                var currentData = component.get('v.data');
                var newData = currentData.concat(data);
                component.set('v.data', newData);
                component.set('v.loadMoreStatus', 'Please scroll down to load more data');
            }
            event.getSource().set("v.isLoading", false);
        }));
    },
    
    handleSelectedRows: function (component, event, helper) {
        var data = component.get('v.data');
        var selectedRowList =  component.get("v.selectedRowsList");
        console.log('selectedRowList-' + selectedRowList);
    },
    
    handleSelectedRow: function(component, event, helper){
        var selectedRows = event.getParam('selectedRows');
        component.set("v.selectedRowsCount", selectedRows.length);
        let obj =[] ; 
        for (var i = 0; i < selectedRows.length; i++){
            obj.push({Name:selectedRows[i].Name});
        }
        component.set("v.selectedRowsDetails", JSON.stringify(obj) );
        component.set("v.selectedRowsList", event.getParam('selectedRows'));
    },
    
    handleRowAction: function (component, event, helper) {
        var action = event.getParam('action');
        switch (action.name) {
            case 'new':
                helper.createContactRecord(component, event);
                break;
            case 'edit':
                helper.editContactRecord(component, event);
                break;
            case 'delete':
                helper.deleteContactRecord(component, event);
                break;
            case 'view':
                helper.viewContactRecord(component, event);
                break;
        }
    },
    
    handleColumnSorting: function (component, event, helper) {
        var fieldName = event.getParam('fieldName');
        var sortDirection = event.getParam('sortDirection');
        component.set("v.sortedBy", fieldName);
        component.set("v.sortedDirection", sortDirection);
        helper.sortData(component, fieldName, sortDirection);
    },
})

Lightning Component JS Helper:

({
    getContacts : function(component) {
        var action = component.get("c.getContactList");
        action.setParams({
            "recordLimit": component.get("v.initialRows"),
            "recordOffset": component.get("v.rowNumberOffset")
        });
        action.setCallback(this, function(response) {
            var state = response.getState();
            if (state === "SUCCESS" ) {
                var resultData = response.getReturnValue();
                component.set("v.data", resultData);
                component.set("v.currentCount", component.get("v.initialRows"));
            }
        });
        $A.enqueueAction(action);
    },
    
    getTotalNumberOfContacts : function(component) {
        var action = component.get("c.getTotalContacts");
        action.setCallback(this, function(response) {
            var state = response.getState();
            if (state === "SUCCESS" ) {
                var resultData = response.getReturnValue();
                component.set("v.totalNumberOfRows", resultData);
            }
        });
        $A.enqueueAction(action);
    },
    
    getColumnAndAction : function(component) {
        var actions = [
            {label: 'New', name: 'new'},
            {label: 'Edit', name: 'edit'},
            {label: 'Delete', name: 'delete'},
            {label: 'View', name: 'view'}
        ];
        component.set('v.columns', [
            {label: 'Name', fieldName: 'Name', type: 'text', sortable:true},
            {label: 'Email', fieldName: 'Email', type: 'email', sortable:true},
            {label: 'Phone', fieldName: 'Phone', type: 'phone', sortable:true},
            {type: 'action', typeAttributes: { rowActions: actions } } 
        ]);
    },
    
    getMoreContacts: function(component , rows){
        return new Promise($A.getCallback(function(resolve, reject) {
            var action = component.get('c.getContactList');
            var recordOffset = component.get("v.currentCount");
            var recordLimit = component.get("v.initialRows");
            action.setParams({
                "recordLimit": recordLimit,
                "recordOffset": recordOffset 
            });
            action.setCallback(this, function(response) {
                var state = response.getState();
                if(state === "SUCCESS"){
                    var resultData = response.getReturnValue();
                    resolve(resultData);
                    recordOffset = recordOffset+recordLimit;
                    component.set("v.currentCount", recordOffset);   
                }                
            });
            $A.enqueueAction(action);
        }));
    },
    
    sortData: function (component, fieldName, sortDirection) {
        var data = component.get("v.data");
        var reverse = sortDirection !== 'asc';
        data.sort(this.sortBy(fieldName, reverse))
        component.set("v.data", data);
    },
    
    sortBy: function (field, reverse, primer) {
        var key = primer ?
            function(x) {return primer(x[field])} :
        function(x) {return x[field]};
        reverse = !reverse ? 1 : -1;
        return function (a, b) {
            return a = key(a), b = key(b), reverse * ((a > b) - (b > a));
        }
    },
    
    viewContactRecord : function(component, event) {
        var row = event.getParam('row');
        var recordId = row.Id;
        var navEvt = $A.get("event.force:navigateToSObject");
        navEvt.setParams({
            "recordId": recordId,
            "slideDevName": "detail"
        });
        navEvt.fire();
    },
    
    deleteContactRecord : function(component, event) {
        var action = event.getParam('action');
        var row = event.getParam('row');
        
        var action = component.get("c.deleteContact");
        action.setParams({
            "con": row
        });
        action.setCallback(this, function(response) {
            var state = response.getState();
            if (state === "SUCCESS" ) {
                var rows = component.get('v.data');
                var rowIndex = rows.indexOf(row);
                rows.splice(rowIndex, 1);
                component.set('v.data', rows);
                
                var toastEvent = $A.get("e.force:showToast");
                toastEvent.setParams({
                    "title": "Success!",
                    "message": "The record has been delete successfully."
                });
                toastEvent.fire();
            }
        });
        $A.enqueueAction(action);
    },
    
    editContactRecord : function(component, event) {
        var row = event.getParam('row');
        var recordId = row.Id;
        var editRecordEvent = $A.get("e.force:editRecord");
        editRecordEvent.setParams({
            "recordId": recordId
        });
        editRecordEvent.fire();
    },
    
    createContactRecord : function (component, event) {
        var createRecordEvent = $A.get("e.force:createRecord");
        createRecordEvent.setParams({
            "entityApiName": "Contact"
        });
        createRecordEvent.fire();
    }
})

Output: