JSFiddle - React, Tailwind, and code Playground

HTML

<select id="dropdown"><option val="1">OPT1</option><option val="2">OPT2</option></select>

<table id="table" border="1">
<tr><td>COL1</td><td>COL2</td></tr>
</table>

JavaScript

$('#dropdown').on( 'change', function(e) {
    $('#table').append('<tr><td>COL1</td><td>COL2</td></tr>');
});