What can I take to China? Biltong,masala,bottle of alchol,mealie meal,sweets?

As I know, biltong is not allowed to take. You'd better declare masala and mealie meal at the customs, for they may need to take quarantine check. If the alchol is less than 1.5L, you don't need to declare but you should put them in check luggage. You can take sweets into CN and there is no specific limit for that.
Doctor's note is necessary when you take presciption medicine. If they are OTC medication, you can take self-use amount without the note.