custom-data-table.js

import { LightningElement } from 'lwc';
import { NavigationMixin } from 'lightning/navigation';
import { subscribe } from 'lightning/empApi';

export default class CustomDataTable extends NavigationMixin(LightningElement) {
  data = [
    // data table data
  ];
  columns = [
    // other data table column definitions,
    {
      initialWidth: 120,
      type: 'button',
      typeAttributes: {
        label: 'Create task',
        name: 'create_task',
        title: 'Create task',
        variant: 'brand'
      },
    },
  ]
  

  subscription = {};
  CHANNEL_NAME = '/event/Refresh_Record__e';
  
  _handleRefreshRecord(event) {
	  // business logic to refresh UI
  }
  handleRefreshRecord = _handleRefreshRecord.bind(this)

  connectedCallback() {
    subscribe(this.CHANNEL_NAME, -1, this.handleRefreshRecord).then(response => {
      this.subscription = response;
    });
  }
  
  handleRowAction(event) {
    const { action, row } = event.detail;
    const defaultFieldValues = encodeDefaultFieldValues({
      WhatId: row.WhatId,
    });
    this[NavigationMixin.Navigate]({
      type: 'standard__objectPage',
      attributes: {
        objectApiName: 'Task',
        actionName: 'new',
      },
      state: {
        defaultFieldValues,
        navigationLocation: 'RELATED_LIST'
      }
    });
  }
}