WorkGuru provides an order form function available when creating new purchase orders, it can pre-populate the order with all the products assigned to the selected supplier.  This is useful if you repeatedly purchase the same products from a supplier to ensure you won't forget any line items.

The pre-requisite for this function to work is to ensure products have a default supplier assigned.  Suppliers can be assigned by editing the product details.  Products -> List Products -> Edit Product

When creating a new purchase order, search for and select a supplier

When a supplier is selected, the Add a New Supplier button will change to Build Order Form.

Click Build Order Form and WorkGuru will add every product that has the selected supplier set as a default supplier to the order.

Update the quantity's or add/remove lines as required.  Process the rest of the purchase order as per normal.