That looks weird. I am guessing that someone knows about the mismatch between ccTLDs (where the UK is .uk) and ISO codes (where the UK is GB and Ukraine is UA) and tried to correct something and got it wrong.
its correct in other tables.
.uk being the TLD, and .gb being the ISO 3166-1 alpha-2 code is a quirk of history that comes with .uk being on the internet very early.