how to add payment options to a column

I have a column in Numbers for my music equip expenses.

I have several payment methods, DISCOVER/DEBIT/CASH/

I have seen where one can press the mouse on the cell and those options become available,

How can I have the different payment methods available to select so as to not have to write them in.

What is shown above is what I have to type in, or copy paste I understand there is a way to have my payment options available somewhere in that column to select from.

I am a Numbers newbie and not a business major so if you can help in anyway that is basic I would appreciate it.

NUMBERS 4.3.1

iMac 10.13.3

Thank you in advance for your simplified explanation.

jojoguitar