$re = '/<table.*?>(([\s*].*(\s*))+)?<\/table>/';
$str = '<table width="100%" cellspacing="0" cellpadding="4"><colgroup> <col width="85*" /> <col width="85*" /> <col width="85*" /> </colgroup>
<thead>
<tr valign="TOP">
<th width="33%">Th1</th>
<th width="33%">Th2</th>
<th width="33%">Th3</th>
</tr>
</thead>
<tbody>
<tr valign="TOP">
<td width="33%">C1</td>
<td width="33%">C2</td>
<td width="33%">C3</td>
</tr>
<tr valign="TOP">
<td width="33%">C4</td>
<td width="33%">C5</td>
<td width="33%">C6</td>
</tr>
<tr valign="TOP">
<td width="33%">C7</td>
<td width="33%">C8</td>
<td width="33%">C9</td>
</tr>
</tbody>
</table>
<h2>Title</h2>
<table width="100%" cellspacing="0" cellpadding="4"><colgroup> <col width="85*" /> <col width="85*" /> <col width="85*" /> </colgroup>
<thead>
<tr valign="TOP">
<th width="33%">Th1</th>
<th width="33%">Th2</th>
<th width="33%">Th3</th>
</tr>
</thead>
<tbody>
<tr valign="TOP">
<td width="33%">C1</td>
<td width="33%">C2</td>
<td width="33%">C3</td>
</tr>
<tr valign="TOP">
<td width="33%">C4</td>
<td width="33%">C5</td>
<td width="33%">C6</td>
</tr>
<tr valign="TOP">
<td width="33%">C7</td>
<td width="33%">C8</td>
<td width="33%">C9</td>
</tr>
</tbody>
</table>';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php