What you have there looks like it should work. However, have you tried including the tblCcontacts Last Name and First Name in your query first, and then calculating MovedBy.
Try adding Fields:
LastName: [tblContacts].[Last Name]
FirstName: [tblContacts].[First Name]
and then change MovedBy to:
MovedBy: [LastName] & ", " & [FirstName]
Other than that I would check the table joins and ensure that you actually have records in tblContacts that meet the join conditions.
Hope this helps.
Hope this helps