Yesterday, my daughter finished the third of her three public exams in Honour Moderations, the first year exams taken by law students at Oxford. She had a paper on Monday, Wednesday, and Friday of the ninth week of term. She is tired but happy, and went punting with her college lawyer cohort after the final exam. She will have a chilled-out Trinity Term (she is, in Oxford parlance, "Trinifree").
Her next public examinations will be Schools: seven papers taken over two weeks in the summer of 2027.
When I read Modern History at Oxford several decades ago, I did Prelims, three exams taken at the end of the first term, and then Schools: ten papers over five days at the end of the third year, two papers a day. It was fine. The history course has changed since then.
Undergraduates usually take one or more Collections (practice exams set by their college) each term. These are for monitoring purposes only. Collections are not university exams and the results don't influence the student's degree classification.