Here's how I do it sometimes:
<?php
define ('NEWLINE', "\n");
define ('NEWLINEx2', "\n\n");
define ('TAB', "\t");
define ('TABx2', "\t\t");
define ('TABx3', "\t\t\r");
$table .= '<table border="1">' . NEWLINE;
$table .= TAB . '<tr>' . NEWLINE;
$table .= TABx2 . '<td>something</td>' . NEWLINE;
$table .= TAB . '</tr>' . NEWLINE;
$table .= '</table>' . NEWLINE;
?>
Maintains nice code highlighting. 😉