Will android tablets from US work in the UK?
This may depend somewhat on the device, so I would try to narrow down which one in particular you want then try to figure out what other people are saying about it. Having said that, I know lots of people on XDA are using US Verizon Xooms in Europe without any problems (minus 3G, of course, which you said isn't a problem). There's a thread about this here. Some have also noted that you can flash European firmware onto the VZW Xoom without any problems, but I'm not sure what the caveats are and I don't know if that would work on other devices.