Looks like a normal list for a pastoral deputy. They aren't taking the piss, that's life at that level.
Things that are "missing" that other SLT will be doing include:
The timetable (starts about February)
Curriculum planning (with every exam changing this is massive)
Assessment and data (with no levels and unclear 9-1 this is also massive)
Line management of heads of year
Student Council and Student Voice
Assemblies (running / scheduling)
Calendar (planning)
Trips (ensuring all the gazillion forms have been completed).
Duties (scheduling them and checking they are done)
Running "collapsed" days so that trips can go ahead.
CPD (this might be covered under staff training, but also involves approving training courses - budgets are so low and exam board training is high on the agenda).
Marketing
Newsletters / whole school letters
The website
Y6 Open evening and/or open mornings
Year 6 transition
Sixth form open evenings / interviews
Sixth form transition
The PTA
Governors' meetings
Overseeing all appraisal and moderation.
Judging competitions
School photographer - organising which year groups and which lesson they come out of.
Overseeing display for learning
Organising how the head girl/boy will be selected
Parents evenings - scheduling / letters home / setting up
Also the "bursar" jobs - he or she is normally on the SLT - site team, cleaners, the whole budget, health and safety, fire regulations, the census, external contractors, etc.
On top of that also to include:
Dealing with the latest fight or issue (this can take days)
Exclusions and reintegration meetings
Parents
Local complaints
Regular work experience requests from people considering teaching.
Governor visits
Ofsted's latest guidance