estrarre dati da sito javascript

<?php
$filename = "dati.xls";
header("Content-Type: application/vnd.ms-excel");
header("Content-Disposition: inline; filename=$filename");
?>    

<table class="tab">
    <tr>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
    </tr>
    <tr>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
    </tr>
    <tr>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
    </tr>
    <tr>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
    </tr>
    <tr>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
        <td>dato</td>
    </tr>
</table>