JSFiddle - React, Tailwind, and code Playground

HTML

<table id="tableOne">
  <tr>
    <td>One</td>
    <td>Two</td>
    <td>Three</td>
    <td>Four</td>
  </tr>
</table>

<table id="tableTwo">
  <tr>
    <td>One</td>
    <td>Two</td>
    <td>Three</td>
    <td>Four</td>
  </tr>
</table>

<input type="button" value="test" id="testButton"/>

JavaScript

$('#testButton').click(function(){
    $('#tableTwo td').prev().after('<td>test</td>');
});