Multiple Rows in a using wp_query

Get all of your posts in one query, then count the iterations of your loop.

Pseudo-code follows.

if ( $query->have_posts() ) {
$i = 0;
                while ( $query->have_posts() ) {

// If $i is 5 (5th post), end one row and start the next
if (++$i == 5) {
echo '</tr><tr>';
}
// the rest of your loop output