JSFiddle - React, Tailwind, and code Playground

HTML

<a href="javascript:void(0)" id="showContent">Show Content</a>
<br><br><br>
<table width="400" border="1">
    <tr id="mainContent">
        <td height="30" style="display: none;"> THIS IS MAIN CONTENT </td>
    </tr>
</table>

JavaScript

$('#showContent').click(function ()
                             {
                             
                             
                             
       $('#mainContent > td').slideToggle('slow');                      
                             
                             });