The following code shows how to set table header width with span6, span2 and span4.
<!DOCTYPE html>
<html>
<head>
<link
href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.1/css/bootstrap-combined.min.css"
rel="stylesheet">
</head><!-- w w w . j a va2 s .c om-->
<body style='margin:30px'>
<table class="table table-bordered table-condensed">
<thead>
<tr>
<th class="span6">span6</th>
<th class="span2">span2</th>
<th class="span4">span4</th>
</tr>
</thead>
</table>
</body>
</html>
</body>
</html>