What is Full Fuel load and how does it differ from Fuel Capacity?
The payload does not include the fuel itself. Payload means the total weight of all passengers, their baggage and all cargo on board. If you add this payload weight to your OEW (Operating Empty Weight), you get the ZFW (Zero Fuel Weight). On top of that you have to add the fuel.
The payload you quote is the maximum payload you can have if you also have full fuel on board. This is to make sure that the total weight of the aircraft remains below MTOW (Maximum Takeoff Weight) or possibly maximum taxi / ramp weight. If you fly with less than full fuel, you might be able to load more payload (as long as you stay below maximum ZFW).