A point of frustration with Numbers users is that Pop-Up Menu cells must be populated with a list of typed values. Often it is useful to get these values from another table instead. While there is no easy solution, you can simulate a dynamic pop-up with a special technique that involves creating the Pop-Up Menu in the second table and pasting it into the first. This method requires a manual update of the Pop-Up Menus when the selections change, but can handle large lists.
Thanks for this video, I had forgotten how useful Pop-Up menus can be.