All you can eat is actually quite specific, but for knuckleheads like yourself it is usually clarified in writing in other places. It's all you can eat while at the establishment.. not all you can take. They don't advertise it as "unlimited" either as many places in busy markets have a posted time limit. This is clearly part of their terms of service as most buffets I know both clearly state that you can't use takeout containers and many have a posted price for taking out food by the pound or piece. You are not digging yourself further dude.