It seems that you would need to issue a tableupdate(.t.) for each table you are adding data to.

Another model for handling a one-to-many table situation can be found in the Tastrade example in the order entry form. This approach shows the parent fields and below a grid for the child records. Data is entered directly into the grid using a right-click on the grid. The right-click brings up a small popup with the options to add a record or delete a record.