Here are a few ideas he might find interesting. Fossils and minerals might be a hobby for him. Look at maps? Have a globe in the house and try some songs in other languages? Even coin or stamp collecting can be surprisingly fun for young children. And keep up the sport and social side of things.
My DD was the same. Just go with it and let him read lots. The Hobbit was a hit at 6 for us. With my DD we worked on social skills, small motor skills (truly awful!) and let her fly. DD2 still flies - socially too now though I have long given up on small motor skills, the writing is finally legible! Sounds like school making sure that he is not bored - which is key. Avoid any suggestion of moving up a year. It may solve the academics but I know several who did and it causes social problems in teens and even earlier for boys as they get left behind in sport. Enjoy! Any questions your DS asks that you can't answer then have fun researching.
My DD seems at a similar reading level (although she could not read Flat Stanley before starting school but read her first Flat Stanley book last week)...She is currently in reception btw.
She also taught herself to read before starting nursery (but did not get any books from nursery - so the library was our friend )...
DD goes in and reads with the yr2 teacher once a week (and then picks a new book out to read at home) she also has her phonics/numeracy lessons with a TA with her and another boy who is at a similar level (not with the rest of the class) and has extension homework every week...
TBH I have zero concerns about her not feeling part of the reception class as everything she does is so spread out iyswim (she also has 3 sessions of physio/OT a week out of the class)...
She is going to sit the yr1 phonics test at the end of this yr (with the current yr1s to get it out of the way). Other than that I am happy for her to run around and play with her friends.
Although as other posters have said I think yr1 might be the year that I may have to be a bit more on the ball in terms of extension but the main thing is that she is happy
We've got a DD who was in a similar position reading wise (although not able to talk about the waning gibbous ) and I think what your school is doing sounds good. It is hard to strike a balance between social and academic needs; although in a way it is easier in Reception when there is a lot of play.
The risk later on is that he learns to coast, but that's probably for further down the line.
I agree with Lijkk about not accelerating too far, we've been advised to think about breadth. On those lines things to think about at some stage include music lessons (good for teaching concentration and practice) and also taking him out for the occasional learning day (we take DD to homeschool events at our local science centre and school are quite happy about that).
he sounds happy as he is, like the programme they are already doing is on the right track. If he kept accelerating the way he is he could end up ready for GCSEs when he's 10 (would you like that)? So I think it's fine, as long as he's happy, if he treads water somewhat while the others catch up. I am convinced that success at school is mostly about the social life. It's great it sounds like he has that sussed, too. But the odds are some things will still be challenges for him, like maybe art, writing, rule-following, sport, science or math.
I think it's fine to ask teacher how best to keep him enthused about learning, like any other child he will have some weaknesses to work on while building on his strengths.
Largely unknown to us, he taught himself to read just before he was 4 so when his nursery first handed out reading books he read everything they gave him perfectly until in the end they gave up on banded books and just told him to pick what he liked. Before starting school he could happily read Roald Dahl, Flat Stanley etc...
He's also always been fascinated by how things work/why things are the way they are. He reads lots of books about Space, science etc that he chooses at the library and seems to memorize the information almost immediately so he can tell you all about the water table, how electricity is generated, causes of volcanoes, earthquakes etc...
Both DH and I were early readers so didn't really think any of this was unusual but since he's started school it's become clear that he is quite a long way ahead of all the other children.
By way of example, they do show and tell each week - DH took a model of the solar system and talked the class through the names of the planets before explaning to them about the phases of the moon. After he told them all about the 'waning gibbous' (I had to look it up myself - apparently he read about it in one of his books) his teacher said she thought he was gifted and needs extending.
He has different reading books and different writing exercises from the rest of the class (who are all reading the same book as the basis of their phonics lessons) which he does either independently or with a teaching assistant when the rest of the class are doing more simple work.
His handwriting is still pretty spidery so I've suggested that he do a bit more practice on that if the work everyone else is doing isn't suitable for him and I think revisiting all the basic phonic sounds with the other children isn't a bad thing anyway as it will reinforce his spelling.
I'm keen for him to join in with the rest of the class as much as possible - he has made good friends and really enjoys school so I'm a bit worried that all this having different work to everyone else might make him feel too 'different'. On the other hand I don't want him to be bored either.
Anyway (sorry this has got very long) we have a meeting coming up with his teacher and I could do with some advice/suggestions of things to ask.
What do you think? Is it better to just downplay all of this for now and wait for the others to catch up a bit or should I push for them to keep up the pace he seems to have set for himself?