The powerboard is doing what it is supposed to do, you are overloading it, so it is tripping out. A kettle is typically 10A, as is an electric frypan, so that's 20A you are trying to draw from a 10A powerboard.
Just boil the jug before you use the frypan. Don't use both at once.
You could get a multi-box power outlet without an overload device on it and rely on the circuit breaker for your overload protection.
You can't buy those in Australia. All powerboards sold here must have integral overload protection.
I think that maybe there's something wrong with either your power board, or one of your appliances leaking earth. We run our kettle, toaster, fridge & coffee dripper at the same time (powered sites) & don't have any probs.
You might have them all plugged in at once, but are they actually
running at the same time? If they are then the overload in your powerboard is faulty.