Replace title column in post list with post meta value

You can use the_title filter.

add_filter('the_title', 'my_meta_on_title',10, 2);
function my_meta_on_title($title, $id) {
  if('booking' == get_post_type($id)) {
      return get_post_meta( $id, 'booking_first_name', true ).' '.get_post_meta( $id, 'booking_last_name', true );
   }
  else {
      return $title;
  }
}