Change the row height of table

Hi,

I tried to change the height of pdf table header by inserting below code. I set options as below.

Render As HTML = checked
Use the PHP eval function instead php_eval = checked

PHP Code Before Output

<?php
$h = 200;
?

reference: https://www.drupal.org/node/2199555

Issue is header cell height will not change. Any help highly appreciated.