The more you expose them to, the more they should be able to handle - so appropriate varies depending on what exposure children have had.
So you'd have to get a feel for what they can do by asking them to try out a task you have for them.
My two have ALWAYS done chores from the second they were able to walk (but not alone obviously!) So I believe you'd have to start small - give small tasks and see how they manage.
Mine filled the washing machine with clothes and I'd do the chemical part for a long time until recently (almost 9 and 11) I started this when they were probably around 2/3, have their own list in shops and thats their task, vacuum, fold clothes and put away, upkeep their rooms. My youngest voluntarily cleaned the toilet out of the blue a year ago and still does here and there.
Honestly everything, help with cooking. I have expectations that both of them will be fully capable managing in life and I refuse to do it all alone as I feel we are a team in the home. Whatever chore you're doing and you think they can manage to help (even being annoying for now) little by little doing it with you they will learn the ropes and when older be able to do it unsupervised. So start them young!
I can't think of anything they don't do, the 9yo refuses to use my knives but they're a professional set and she's genuinely scared (even though blunt knives are more dangerous!) So she will peel, prep and clean what she can but she is genuinely scared of chopping harder veg that her little serrated knife won't cut through - so I don't force her. But she's been cutting since age 2 or 3? Obviously we started with those asda toddler cutlery and bananas but we were forcing confidence ASAP!
Anything you are doing for the home, is a team effort!
Now I'm able to say 11 go vacuum and 9 go fill the dishwasher and I'm going to walk the dog! Oh I never line up job after job unless there's something happening - like if we are due a party of any sort we do sometimes line up jobs because they see the need and value in working together but they get a good amount of breaks vs me!
Process may be initially hard OP but at some point once they get the hang (especially as the younger ones grow) you should be able to split tasks and things are easier!