In order to edit tables, they need to have uniquely identifyable rows, see the doc.
Sorry for the term, a master table is the one that contains the primary key, the "detail" table references the primary key in that master table, a "master-detail" relationship.
Create primary keys in *every* table, unless you have a very very good reason not to do so (and these are rare).
Regards, Andreas
---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings