tblUsers is for local user accounts. While that may be what your looking for, it will include all local user accounts. Since not all local user accounts have account details (the guest account for example), you will get results that are basically blank; even ones that are disabled.
I have a sneaking suspicion you actually want tblADUsers, which will then pull the 'Display Name' of your Active Directory users based on the AD information.
-Kris