I'm a HLTA (previously NNEB Dip, STA etc)
Yes, I lead groups in two classes. Phonics x2a week in two classes, 2groups in one class.
Guided Reading x2 classes.
Maths group in one class, support in class with other group.
Nurture group x2 a week ( varies year to year) and I'm a qualified Nurture Practioner.
Lesson plans.
Sometimes I am given them but often just verbal at the beginning of lesson.
Prep.
Yes, I get paid for some of this time but do a lot in my time eg. Writing spelling words in 28 books as I link to handwriting so ten words each week. Spelling lists too but photocopy those. Nurture group planning.
Marking.
Yes, I mark books on a daily basis. I always mark my group but also mark class work as I take classes when teachers are at meetings, hymn practice or parent/ staff meetings. I sometimes stay and mark to help a teacher with a young family to get home sooner.
I teach during PPA time every week and occasional cover for sickness, mainly in those classes. Obviously I mark all that work.
In the past I have also supported the SENCO and can complete paperwork for referrals, attend meetings and work with EAL pupils.
I have Level 4. Two courses at Uni. All our TAs ( except one) are Level 3 or above. We have four HLTAs. It is quite a large primary.
Level 2 should not be working outside the class room. We have one Level 2 who has just started with us.
Hope this helps. Every TA in our school has a slightly different role.