Are you trying display the entire product list and they enter a quantity for items they want to order?

From a browser-efficiency standpoint, I'd say a better approach would be to start with a table that has only one empty row, have the user select the item from a drop down, and then enter a quantity, and add rows as needed for additional items.

In that case, your item list would be a drop down so for every row the add they just pick the item/product and enter the quantity; that way the form would only need to submit/capture data for the items they actually need instead of building out and submitting the entire table for every order.

However, when you're loading all rows from a table, you just set the field as a single line, check the box for "add as new rows" and mark the fields/columns loaded from the database as read only.