You must replace this line
tblTable.Initialize(Me, "Users", 3)
by this line
tblTable.Initialize(Me, "tblTable", 3)
You set Users as the EventName but you call the routines tblTable_Click and tblTable_HeaderClick ?
You could also leave tblTable.Initialize(Me, "Users", 3) as it is
and rename the event routines Users_Click and Users_HeaderClick
Best regards.