The marking is a full-time job on its own (marking 1 book - 20 minutes. Times the 300 kids you teach every 2 weeks, insane!).
Reports.
Schemes of work (where every lesson is planned as a 4 part lesson). Given that most teachers teach 7 or 8 classes, that is 7 or 8 schemes of work every 6 weeks. One will take hours.
Books read to support what is being taught.
Data entry (some schools do this monthly).
Mock / practise exam papers (again, monthly in many schools).
Typed up lesson plans for every single lesson (a total waste of everyone's time but almost every school requires them now), with individual students with various special educational needs referenced in them, for the specific adaptations being made for them (e.g. little Billy's work printed in font 18, on yellow paper, little Jessica with 50% TA time, little Arlo given sentence stems...)
Behaviour reports.
All of this done outside of school time because in school time, obviously the teacher is in front of 32 students. Plus lunch duties, break duties, meetings, bus duties, breakfast clubs, revision clubs, homework clubs, initiatives, training sessions, moderation sessions.
Teaching is an 80 hour a week job. It's a full-time admin job, with teaching on top. Which is insanity and is why 1) We can't retain teachers and 2) We can't recruit new teachers for training.