Please can anyone tell me which countries near Thailand do not require a whole passport page for visas/ stamp on arrival for a UK/British passport holder

Any feedback would be greatly appreciated.

You could an e-visa for Cambodia, you print the e-visa on a sheet of paper.

You will still need to be stamped in and out of Thailand and Cambodia, which will take up at least half a page.

For Singapore or Malaysia you wouldn't need visas but would still get the appropriate entry and exit stamps.

Burma and Thailand entry/exit stamps are pretty small - get several on a page. Most visas are full page - its easier to refer to them then. E-Visas as TOG said is a possible exception to the latter, but as he said will still mean the former (stamps out/in)

From recent experience, Malaysia is a good bet, I use the Sungai Kolok / Rantau crossing .. You dont have the full page visa sticker and you can talk to the immigration guys to squeeze in stamps into those little gaps left in your passport. Thai immigration have been quite good on the return, helping me save pages.

thank you