PHP Code:
<?php
$message = 'Hi there';
echo '<table><tr valign="top"><td>' . $message . '</td></tr></table>';
?>
Keep in mind that a good way of organizing your print and echo statements is by concatenating strings. The whole point of double quotes is to allow interpolation. Personally I prefer inline html over echo.
PHP Code:
<?php $message = 'Hi there'; ?>
<table><tr valign="top"><td><?=$message?></td></tr></table>