Your issue, as alluded to above, is one of time. The more you head into central London, the longer time it takes but the more likely it is that the restaurant will be in full swing - by the time you get to Notting Hill, for example, everything will be going strong for seating at 10pm. Conversely, out of town, people eat earlier.

I would second Chiswick (probably 25-30 minutes away by cab), but also suggest Gilbeys in Eton which is 10 - 15 minutes away by cab and is good and atmospheric, but not in Michelin star territory. Also, the Palmer Arms in Dorney, only a couple of minutes further. Both of these are far better than anything you would get in a Heathrow hotel and far more atmospheric and special.

Bray is wonderful but takes longer than Chiswick. The Waterside Inn, if you like traditional food, is as good as it gets, but I wonder what the atmosphere will be like if you are only sitting down at 10pm. However, if you are in Bray, also try the Hind's Head.