wordpress get_post_meta give only first value

You have the parameter of get_post_meta set to true which returns single result, set it to false or remove it completely.

 $dump_array = get_post_meta(get_the_id(), '_as_roomname')
 //check whats in the array
 var_dump($dump_array);

// or loop for output
foreach( $dump_array as $dump )
echo $dump;