JSFiddle - React, Tailwind, and code Playground

HTML

<div id="switchGridDiv"  style="width: 100%">
  <table id="flexSwitch" class="flexigrid"> 
   <tbody>
       <tr><td>asd</td></tr>
   </tbody>
  </table>          
</div>

CSS

#flexSwitch tbody tr td{
   background-color: red;
}

JavaScript

$(document).ready(function(){

    var newTbl = '<tr><td>1</td><td>1</td><td></tr>';   

    $('#flexSwitch > tbody:last').append(newTbl);
    
});