The "$_SESSION['WADA_Insert_tblVendors']" is used on the insert page as there is no record in the database to view until the insert behaviour has occured (to enable any filtering).
After that point you could filter the recordset by the record ID using URL as in "record ID = URL parameter" this is in the simple view of the RS or if its going to be a set record ID use
If you are trying to add and view information to lookup tables your better to use the manage relational table behaviour. If you have 3 tables. Main, second and then the 3rd table(lookup) with info from both main and second