yup that's the basic of lua you can put functions in tables, that is not property of wow.
The fresh tut you're probably looking for has moved in a book
World of Warcraft Programming
there is big chances the guys that made the tut you have read long time ago have wrote the book.
That's an awesome book , I would have named it the bible of world of warcraft programming hehe
if im not wrong I think Kaelten, Cladhaire and Cogwheel wrote it.