Small round hard bump, white underneath flesh on tonsil.just appeared one day. can a ent biopsy this? maybe scan? hasn't got bigger. scared :(

ENT biopsy: An ENT could absolutely biopsy this. From your description it could be a number of possibilities--anything from a viral infection to a papilloma. Recommend seeing an ENT to evaluate i further if it doesn't go away in a week or two.

Tonsillolith: This sounds like it could be a "Tonsillolith" or a "tonsil stone". These are a common and completely benign. You can often see the white top of the "stone" but the base fills a tonsil crypt and can be difficult to remove. You can try irrigating with a waterpik, or gently pushing on the base of the stone with a finger and trying to push it out.