One of the differences between the server behaviors in DataAssist and the standard Dreamweaver ones is that with DataAssist, there is no limitation to the number of insert, update or delete server behaviors you can add to a page. So you can add one DataAssist Insert Record behavior for one table and another for a second table.
On relational tables, DataAssist contains a dedicated server behavior called Manage Relational Tables intended just for that situation.
Best - Joe