The amount of homework seems a lot, however, as he’s tracking so far behind it’s likely the extra is to try to address this.
Do they suspect a SEN diagnosis? Has he been assessed by and Educational Psychologist?
Spellings are useless for a child who can’t read so I’d ignore those. Is also ignore the stuff about ‘what’s the setting of the book’.
How much do you read to him? Does he LIKE books?
I’d suggest some routines put in place to try to make progress and stick to:
Reading books to him
Working your way through a recognised phobics course with him
Practising his handwriting
Learning numbers and counting
If you can afford it there are lots of ‘getting ready for school’ type books which are helpful.
FWIW, my son has HFA - his reading is exceptional but his writing was utterly woeful. Since September we have 10mins a day writing practise and the improvement is amazing - It’s fine from illegible scratches to properly formed legible words.
I hope you can make some progress.