Is it possible to insert a table in a fieldset?
See http://wp46.demo.civicrm.org/wp-admin/admin.php?page=CiviCRM&amp;q=civicrm%2Fadmin%2Fcustom%2Fgroup%2Ffield&amp;reset=1&amp;new=1&amp;gid=4&amp;action=browse where you have an example of a bunch of fields for 


medication
frequency
amount


is that what you need?