.browseCategoryImage {
background: #FFF url( 'images/browsecategorybg.png' ) no-repeat  center center;
vertical-align:top;
height: 200px;
text-align:center;
}

<?php if( !defined( '_VALID_MOS' ) && !defined( '_JEXEC' ) ) die( 'Direct Access to '.basename(__FILE__).' is not allowed.' ); 
mm_showMyFileName(__FILE__);
 
$iCol = 1;
if( !isset( $categories_per_row )) {
	$categories_per_row = 3;
}
$cellwidth = intval( 100 / $categories_per_row );
 
if( empty( $categories )) {
	return; // Do nothing, if there are no child categories!
}
?>
<br/>
<table width="100%" cellspacing="0" cellpadding="0">
<?php
foreach( $categories as $category ) {
	if ($iCol == 1) { // this is an indicator wether a row needs to be opened or not
		echo "<tr> \n";
	}
	?>
 
	<td class="browseCategoryImage" width="<?php echo $cellwidth ?>">
		<br />
 
 
 
	<a class="browseCategoryTitle" title="<?php echo $category["category_name"] ?> " href="<?php $sess-> purl(URL."index.php?option=com_virtuemart&amp;page=shop.browse&amp;category_id=".$category["category_id"]) ?>"> 
			<?php
			if ( $category["category_thumb_image"] ) {
				echo ps_product::image_tag( $category["category_thumb_image"], "alt=\"".$category["category_name"]."\"", 0, "category");
				echo "<br /><br/>\n";
			}
			echo $category["category_name"];
			echo $category['number_of_products'];
			?>
		 </a><br/>
	</td>
 
 
	<?php
	// Do we need to close the current row now?
	if ($iCol == $categories_per_row) { // If the number of products per row has been reached
		echo "</tr> \n";
		$iCol = 1;
	}
	else {
		$iCol++;
	}
}
// Do we need a final closing row tag?
if (sizeof( $categories ) < $categories_per_row) {
	echo "</tr>\n";
}
?>
</table>