<tr>
<?php
// The Query
$args = array(
'post_type'      => array( 'pratos_dos_dia', 'grelhados_do_dia' ),
'posts_per_page' => 12
);
$the_query = new WP_Query( $args );
$counter = 0;

// The Loop
while ( $the_query->have_posts() ) {
    $the_query->the_post(); ?>
        <td><h2><?php the_title(); ?></h2><br><h5><?php the_field('acompanhamento'); ?><h5></td>
        <td><h5><?php the_field('meia_dose'); ?>€</h5></td>
        <td><h5><?php the_field('dose'); ?>€</h5></td>

<?php
if ($counter % 2 != 0  ){
    echo '</tr><tr>';
}
$counter++;

}
/* Restore original Post Data */
wp_reset_postdata();

?>