To convert Watts to Amps

Watts / Voltage = Amps

Catering 8100 watts/ 240 volts = 34 Amps

Marquee 6190 watts/ 240 volts = 26 Amps

Total 34 + 26 = 60 Amps

The above example used a 63A, 240v distribution system sited near the disco. A 32A feed from the 63A board was run to the catering marquee where a separate 32A distribution board was used, plus an additional 16A cable. All the main marquee lights, heating and disco were plugged into the 63A board.
You would need a single phase 18kVa generator for the above example.