If you mean something like a form containing an order and the sub containing the order lines, then the answer is yes.
Create the order and orderline entities. Associate the orderline to the order so that the relation is 1:*.
Create a page with a dataview for the order entity and within this dataview add a datagrid and make sure that you select the orderline over association. Fix the errors by creating the NewEdit page for the order lines and you’re good to go.