The order rows of a purchase order appear in a table in the lower section of the window, once you have loaded an existing order or imported a new order.
The table shows all the order rows. If the import file contains several different purchase orders and all have been imported, then the order rows are separated into different orders by a bold black line. You can also see that the order header information changes when you move the cursor between order rows that belong to different orders.
You can right-click in an order row and select Test schedule in the Info menu.