Table validated value set not found when creating Service Extended Attributes mapping

When setting up service extended attributes that use a table validated value set, the value set is not found in the selection list in the Service Requests extended attributes configuration form.  I cannot seem to find any help in the documentation to resolve this issue.  Does anyone know if table validated values sets are allowed in service extended attributes mapping?  Also would appreciate any implementation documentation that might help me figure out if my setups are a problem.  Thanks for any help you can give.