Service crew is just a new name for restaurant and catering staff. If you are service crew member you may serve food, take orders, look after customers or do other work related to working in the hospitality industry. THe most likely role for a service crew member is of a waiter.
Hi Radz, well if we have a team, we need a service crew, regardless of what services we are providing, so that a crew can pick up where input is needed for successful business for example. An airline would have a well trained service crew at all levels of the needs of flight and safety for example. Guess you have more ideas too. Hope useful