Артист,
<html>
<head>
<style type="text/css">
body.show table{
border : 1px solid #FF0000;
padding : 5px;
margin : 5px;
}
</style>
<script type="text/javascript">
function main()
{
document.body.classList.add("show")
}
document.addEventListener('DOMContentLoaded', main)
</script>
</head>
<body>
<table border=0 cellspacing=0 cellpadding=0>
<tr>
<td>dsfsdf</td>
<td>dsfsdf</td>
<td>dsfsdf</td>
<td>
<table border=0 cellspacing=0 cellpadding=0>
<tr>
<td>dsfsdf</td>
<td>dsfsdf</td>
<td>dsfsdf</td>
<td>dsfsdf</td>
</tr>
</table>
</td>
</tr>
</table>
</body>
</html>