I work Long Haul for QF.
I don't mind pax coming into the galley for a chat, in fact it helps pass the time.
I guess what can be a little annoying is those that outstay their welcome or can't work out when your busy or when its appropriate to leave you alone.
If you've just finished doing a bar service, then a meal service, then handing out snacks and a water run, the carts have just been exchanged and the lights have been turned down low and the galley curtains have been pulled closed, it usually means its feeding time at the zoo. Probably best just to leave it 30 mins or so before cheerily walking in for a chat.
The only other time I want you absolutely out of the galley is when we're getting ready for a meal service. Basically, its easier if your out of the way.
But for the rest of the time I'm more than happy for pax to come and chat, ask questions, while away the time or generally show an interest. A lot of the time we have to take a punt on who wants to chat and who doesn't, so if you take the initiative most flight attendants will happily chat.