You will need this licence to operate a major amusement park. A major amusement park is a workplace that has at least four amusement devices, including at least one class 3, class 4 or class 5 amusement devices under AS 3533.1 - 2009 (Amusement rides and devices Part 1: design and construction), or a high structure water slide at least 10 metres high.
If all the rides at a workplace are for a temporary event (such as an agricultural show or school fete) it is not a major amusement park and does not need this licence.