My DS is also 3. He would love most of this (and already has a fair amount of it
Disclaimer: not a stealth boast, much of it is second hand!)
I agree with others though, it's far too much. But you asked about suitability so here goes:
Baby annabels brother-no, limited play,
Jcb digger ride on-no, limited use (DS has a second hand one, glad I didn't pay full price),
Magic sand-no, messy,
Play dough play date set-yes,
Balance bike-yes ( DS's most favourite thing, fresh air, exercise, what's not to love?!)
*Bike helmet,
Play foam-too similar to Play Doh, don't get both,
Mr Potato Head-yes,
Remote control car-no, too old. consider the helicopter listed below or remote control Thomas instead,
Toot toot school-no, limited use/will outgrow quickly,
Toot toot remote control set-as above
Fireman Sam Pontypandy play set-this OR Postman Pat/Thomas set,
Postman Pat play set-this OR Fireman Sam/Thomas set,
Crocodile dentist-no, too old/limited use,
Teletubbys talking soft toys x 4-no, too young/limited play,
SpongeBob walks talkies-yes (adding similar to DS's list!)
Gelli bath-no! (way too messy and gloopy for me!)
Lady bird night light projector-no, pretty but limited use,
Lego duplo basic bricks-yes,
Lego duplo rocket-yes,
Lego duplo tractor-yes,
Wooden pirate ship-yes, OR the aeroplane,
Rocking caterpillar-no, too young (sold DS's rocking horse),
Chad valley trampoline-no, too young (sold DS's),
Tumble train-no, nightmare toy!
Chad valley aeroplane-yes, OR the pirate ship,
Pop up pirate-no, too old, limited use,
Tomy foam cone factory-yes (also added to DS's list!)
Chad valley light and sound fire engine-yes,
Extra toot toot RC car-no (see above),
Chad valley grand piano-no, limited use,
Track master Thomas shipwreck set-this or Fireman Sam/Postman Pat set
Bus toy-yes,
Playmobil water park play area-no, too old/limited use,
Dinosaur egg-no,
IKEA easel-yes, plus pens/chalks/magnets etc,
Desk and chair-no, better for when he's older,
My first helicopter-yes, OR remote control Thomas. (Helicopter looks good but my dog would kill it!)
Power rangers figure-no, limited use/too old,
4 talking dinosaurs-no, limited use/too young,
4 Disney DVDs-maybe (but can get lots on sky/sky go/Netflix etc)
Please consider buying second hand if you haven't already. At 3 your DS won't know or care if the toys are new (and no one else will either), you'll save a fortune which can be spent elsewhere (eg. other people's gifts, clothes for DS, days out, etc), it'll bother you less if he doesn't play with the items as much as you'd hoped, you won't have to unbox and set toys up on Christmas Day as they'll be ready to play with (which is very important to children), and you can sell/pass them on (if they're in good condition) when he's done with them. So many toys are barely used and sold on for half the original price or less in great condition, why waste money on packaging?
There are local selling sites all over Facebook, or there's EBay, gumtree, second hand shops (one near us specialises in baby and children's goods), specialist local markets, etc.
I hope your DS has a fab Christmas, please don't overdo the gifts, it's quality (of play) that matters and he'll love the magic whatever Santa brings him!