Артист,
<html>
<head></head>
<script type="text/javascript">
function main()
{
var table = document.querySelectorAll('table')
var i = -1, l = table.length
while(++i < l)
{
table[i].style.border = "1px solid #FF0000";
table[i].style.padding = "5px";
table[i].style.margin = "5px";
//alert(i + ' из ' + l + '\n' + table[i].innerHTML)
//table[i].style.border = 0
}
}
document.addEventListener('DOMContentLoaded', main)
</script>
<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>