In Lightning Web Component lightning-datatable tag, draft-values and onsave attributes can be used make editable data table.

Sample Code:

HTML:

<template>
    <lightning-card>
        <div class="slds-m-around_medium">
            <lightning-datatable
                    key-field="Id"
                    data={records}
                    columns={columns}
                    hide-checkbox-column
                    draft-values={draftValues}
                    onsave={handleSave}>
            </lightning-datatable>
        </div>
    </lightning-card>
</template>

JavaScript:

import { LightningElement, wire } from 'lwc';
import fetchAccounts from '@salesforce/apex/AccountController.fetchAccounts';
import updateAccounts from '@salesforce/apex/AccountController.updateAccounts';
import { refreshApex } from '@salesforce/apex';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';

const columns = [
    { label: 'Name', fieldName: 'Name', editable: true },
    { label: 'Industry', fieldName: 'Industry', editable: true },
    { label: 'Effective Date', fieldName: 'Effective_Date__c', type: 'date-local', editable: true, typeAttributes: {  
                                                                                                day: 'numeric',  
                                                                                                month: 'numeric',  
                                                                                                year: 'numeric'} }
];

export default class Sample extends LightningElement {

    records;
    wiredRecords;
    error;
    columns = columns;
    draftValues = [];

    @wire( fetchAccounts )  
    wiredAccount( value ) {

        this.wiredRecords = value; // track the provisioned value
        const { data, error } = value;

        if ( data ) {
                            
            this.records = data;
            this.error = undefined;

        } else if ( error ) {

            this.error = error;
            this.records = undefined;

        }

    }  

    async handleSave( event ) {

        const updatedFields = event.detail.draftValues;

        await updateAccounts( { data: updatedFields } )
        .then( result => {

            console.log( JSON.stringify( "Apex update result: " + result ) );
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Success',
                    message: 'Account(s) updated',
                    variant: 'success'
                })
            );
            
            refreshApex( this.wiredRecords ).then( () => {
                this.draftValues = [];
            });        

        }).catch( error => {

            console.log( 'Error is ' + JSON.stringify( error ) );
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Error updating or refreshing records',
                    message: error.body.message,
                    variant: 'error'
                })
            );

        });

    }

}

Apex Class:

public with sharing class AccountController {
 
    @AuraEnabled( cacheable = true )
    public static List< Account > fetchAccounts() {
     
        return [ SELECT Id, Name, Industry, Effective_Date__c FROM Account LIMIT 10 ];
         
    }

    @AuraEnabled
    public static string updateAccounts( Object data ) {
        
        List < Account > accsForUpdate = ( List < Account > ) JSON.deserialize(
            JSON.serialize( data ),
            List < Account >.class
        );
        try {
            update accsForUpdate;
            return 'Success: Account(s) updated successfully';
        }
        catch (Exception e) {
            return 'The following exception has occurred: ' + e.getMessage();
        }

    }
     
}

Output: