Show a Particular Page in Drupal 7 Table Pager
I think theme_pager in your case never know about current page, by which it can decide where to add 'page-current' class.

Try passing 'element' parameter the way you are doing for quantity.

$html =  theme('table', array('header' =&gt; $header, 'rows' =&gt; $chunks[$page], 'sticky' =&gt; TRUE)) . theme("pager", array('element'=&gt; $page, 'quantity',count($table_rows)));


While $page will be less than a value of actual current page value. Please see theme_pager to see how it works.