If i get you correctly, you want to display some data in the Form (for reference), correct?
While you cannot add a "Repeater" web part/widget in a Form field, you CAN insert macros.
What i would do is either use a Label field (with no database representation) and put a macro in there, or just put the macro in the "Content Before" / "Content After" of the field you want to do, and use the macro method "ApplyTransformation" (Just make sure the Transformation is type text/xml)
You will need to do a little work to get the data you want in the macro, if it's repeating page types then you should be able to do the below.
{% Documents.Where("NodeAliasPath like '/%'").ApplyTransformation("CMS.MenuItem.Default_Row", "<table>","</table>") |(identity)GlobalAdministrator%}
If it's a custom query you need, i'de have to look up how to run a query from a macro, slipping my mind.