On 'Change Shipping Address' and 'Change Billing Address' pages, under "Choose From Your Address Book Entries", address entries are displayed down to the bottom of the pages, leaving large blank area on the right.

How to display address entries in 2 columns?

I tried to work on file '/includes/templates/my_template/templates/tpl_checkout_shipping_address_default.php' somewhere around
<fieldset>
<legend><?php echo TABLE_HEADING_ADDRESS_BOOK_ENTRIES; ?></legend>
<?php
require($template->get_template_dir('tpl_modules_checkout_address_book.php', DIR_WS_TEMPLATE, $current_page_base,'templates'). '/' . 'tpl_modules_checkout_address_book.php');
?>
</fieldset>

But I'm not able to make address entries display in 2-columns table.
Please help. Thank you.