JSFiddle - React, Tailwind, and code Playground
HTML
<table border="1" id="good" width="100px">
<tr><td>Good</td><td>Table</td></tr>
</table>
<br><br>
<table border="1" id="bad" width="100px">
<tr><td>Bad</td><td>Table</td></tr>
</table>
JavaScript
$(function() {
$("<tr/>")
.toggle(true)
.append("<td colspan=\"2\">zZ1</td>")
.appendTo($("#good"))
.toggle(true);
$("<tr/>")
.toggle(false)
.append("<td colspan=\"2\">zZ1</td>")
.appendTo($("#bad"))
.toggle(true);
});