Remove products or categories from global attributes list

This is my first Zen Cart project... I'm adding in sample products so that I can export the DB and migrate about 1100 products from another cart platform.

I set up two categories today with products that have size/color attributes. That went fine, but when I exported the Attributes (via Easy Populate) I found that all of my other sample products (which had no attributes) were listed too.

How can I make it so that an attribute only applies to a single product or a single category, and not globally to all products in the database like it's doing now?

Does that make sense? I don't want to see blanks for all the attributes that *don't* apply to other products, I just don't want to see them at all.

If these did not exist initially and were only applied to the correct products - then you must be using EP incorrectly