Growingvegetables - you are right, he is bored, like many of the brighter kids in the class.
He really hates literacy homework, as it is as dull as ditch water !
I don't have kids, but I can't remember being set any meaningful homework at that age. Maybe the odd sheet or two of A4 questions, but nothing particularly regular, time consuming, or difficult. I don't have anything immediately relevant to offer except my own experiences, but I do remember being very, very bored at that age. When I was around 9-11 my parents were regularly called in as I was simply refusing to do any work, especially in maths. I would simply not bother with any of it because we were going over the same twaddle again and again.
Case in point: I refused to answer any of the questions about telling the time on an analogue clock. I didn't see the point - I had a digital watch! Nobody explained why it was important and so I didn't do it. I recall having to spend time in the head teacher's office periodically telling them the time, just to prove I wasn't stupid.
It wasn't just boredom, mind you. I didn't really enjoy primary school at all and didn't want to be there. School was a place of crap work which I hated, eye tests to figure out what to do about my
Duane Syndrome and I was a little bit bullied - in retrospect not badly, but the whole shebang was enough that it put me off the place and anything to do with it.
Hopefully that isn't the case for your kid, but maybe he just isn't really enjoying it there and he will find it better in a new school.