Hello! I have created this form:

It is for adding stock when it comes in in a delivery.
"Delivery number" is unique. "Part Number", "Part Description" and "Serial Number" will all be Lookup fields (hopefully cascaded if I can work out how). "Amount to add" is a number. "Add to" will be a Choice field with a list of locations.
What I want is to be able to click "Add" and for it to save the information entered and allow me to enter more data in the same form. So maybe it shunts the entered data down the page and presents me with a place to enter new data. Basically it is recording items coming in from a delivery, there will be many items and I want to be able to record them all using one form/one submission.
I think this can be achieved using Repeating Sections but I'm not quite sure how they work. can anyone help?