Yes.
It has internal counters that tally up the payments it’s authorised.
Good question, @erincandescent should have a good answer for this. But I would guess it either relies on the terminal to provide a conversion value, or it simply won’t authorise offline non-GBP payment via contactless.
Without offline limits there would be places where our cards simply wouldn’t work (such as some bus networks). Additionally the cards can also request to be inserted, in which case they have a separate set of offline contact limits.