Allow customers to add rows to a form


I am creating a form to allow our customers to order new stock. I would like to give them the option to add rows per stock item and have multiple options per row. For example each row on the form would have 4 fields:

  • Item (drop down of all items that can be ordered)
  • Qty in stock (numerical field where the customer can add how much stock they have)
  • Order (a tick box which the customer can tick to advise they want to order)
  • Suggested amount (how much they would like to order)

I am not precious about how this is done and configured (i.e. using logic) but it needs to be one form per order. If allowing customers to add their own rows is not possible I could default the form to have 20 rows and the customer can use as many as they need. I guess the main question is how to display multiple fields that are linked on a form.