Two Column Lists are standard across the POS. You will find them on almost all edit pages.
The list in the left column is the Primary List. It has everything that the POS knows about.
The list in the right column, has only the items that are associated with the particular Food Item you are working with.
These lists are a common theme throughout the POS.
Click on any of the tabs at the top; Fractions, Sizes, Types, Ingredients, Ingredient Modifiers, Sides, Printers, Sales Category, Sales Tax, etc and you will find a Two Column List.
You will also find the common Add/Edit buttons on these pages as well. Some screens have additional features as well.