I want to reply to the note posted above:
"But I haven't been able to define, nor have I ever heard anyone else define, a useful generalized definition for "lookup tables"."
For me it is like pornography: You may not be able to define it, but everyone knows what it is. And since I find the distinction of a lookup table, like the distinction of 'pornography' (vs art?), to be helpful, I don't mind that I don't have a definition that everyone likes. It just works for me/makes me happy, makes me more productive, and in my opinion, makes my database designs more user-friendly for anyone else who might come in some day and have to understand and manipulate that database.
Not that I don't understand the above point too. I'm just offering a response.