From MSDN Page for KeSetEvent
If Wait = TRUE, the routine returns without lowering the IRQL. In this case, the
KeSetEvent call must be immediately followed by a KeWaitXxx call. By setting
Wait = TRUE, the caller can prevent an unnecessary context switch from occurring between the
KeSetEvent call and the KeWaitXxx call.
This statements means Setting on event object to Signaled state and start Waiting for another object to avoid context switching?