Basic idea: a restaurant wherein all patrons are wearing VR goggles that show the theme of their choice.
A party would initially enter into a neutrally-decorated antechamber. While waiting for their table, they would choose several options - what theme they wanted, whether they'd prefer to see
each other as they are or as avatars, etc. Once the table was ready, they'd all be given lightweight VR goggles. The goggles would provide a complete environment, not just an overlay; the patrons would never actually see the physical reality of the dining room. All of the furniture, silverware, plates, etc. would be tracked by computer, either using embedded electronics or visual recognition from cameras in the walls. A central server in the basement would provide virtual analogues for all the actual objects, adjusting for theme. The illusion would never be broken, as everything the guests could interact with would have an actual physical object backing it.
The food: there's no way a computer could keep track of the geometric mess that is a plate of food being eaten, nor do I think the guests would like eating "masked" food. Perhaps the plates could be monitored by small cameras on the goggles and projected directly into the VR environment as they really are?
The people: when dining in a group, you want to see the other person, their body language, facial expressions, everything. If the party chooses to be themselves, this isn't much of a problem - the computer can just do silhouette tracking (which should be easy, as the walls and floor can be painted some flat color - the patrons won't ever see them!) and put the image in the virtual environment. However, if they want avatars, the computer has a much more difficult time of it, especially with the faces. Visual recognition tech is certainly improving, but I have no idea if it's gotten this far yet.
The goggles: they have several difficult constraints. They'd need to be lightweight so as not to interfere with the experience, durable to withstand constant careless use, wireless so the patrons don't have to worry about illusion-breaking wires, and be capable of rendering a relatively realistic scene in real-time. If there was enough wireless bandwidth, much of the processing (entity tracking, phyics, etc.) could be offloaded to a central server. Again, I don't know if the tech has come this far yet.
The marketing: VR tech has been around quite a while. A VR arcade would be much easier than this technological mess; why haven't they caught on? My speculation is that it's due to perception. People are used to arcades being cheap; they don't want to pay more than a couple of bucks for a game, and that makes it hard for a would-be VR arcade mogul to recoup costs, let alone make a profit. On the other hand, people expect to pay ludicrous amounts of money for a meal in a fancy restaurant, and what could be more fancy than this?
With those problems overcome, though, imagine the experience - dine underwater with whales swimming underneath and fish nibbling at your food, or in a Wild West saloon with barfights going on in another corner, or on Io with Jupiter huge in the sky overhead, or...