As a first year history student I compared notes with others when I got here. The general format was the same for all interviews at all colleges but the specifics varied a lot.
As a minimum you get two interviews at your college. Each is typically with two tutors. One is on a set text you get 20-30 minutes to read and make notes before getting questions fired at you on it. The other interview is more general. I got asked about historical British attitudes to Europe (topical re BREXIT), my written work & personal statement but others got asked about what history could tell us about Middle East crisis, US politics etc. and some did not get asked anything on their PS but did get asked about time periods they were studying at school.
There is no single standard as they are looking to get you thinking (it isn’t a knowledge test) but there is advice including mock videos, sample questions etc. on the Oxford website. There were also lots for advice videos from students on You Tube so I assume they are still there. Look at what you can find. Practice with teachers/friends/family. Read your submitted written work & PS. Refresh on any books or topics you mentioned. On the day don’t be afraid to say you don’t know (but use it to show what you do know) or ask a clarifying question. Try not to panic. Try to enjoy it. My first interview did feel like a grilling but I really enjoyed my second as I was talking about stuff I love. Hopefully it showed!