Potresti fare cosi.

codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<head>
<title>Untitled</title>
</head>
<body>
<? 
$numero_news = 5;
ob_start();
include("news.txt");
$content     = ob_get_contents();
ob_end_clean();
$array       = explode('<endofnews>',$content,$numero_news+1);
array_pop($array);
$text        = implode('
',$array);
print $text;
?>
</body>
</html>
File : news.txt
codice:
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>
<table summary="">
<tr>
<td>titolo news 1</td>
</tr>
<tr>
<td>testo news 1</td>
</tr>
</table>
<endofnews>