Ok, here goes...
A Dispatcher for Servisair, is likely to be a co-ordination role. Basically while your aircraft is on the ground, its your responsibility to ensure that everything it needs is where it should be. THings like wheelchairs, de-icing rigs, all need pre-ordering. If you are coaching the pasengers out to the aircraft, thats your call again.
Then you are a also a go-between. Anything that happens between aircraft and ground is likely to go through you. If the crew need catering, you have to get it sorted out. If the captain wants extra fuel, you sort it out. When the crew are ready for boarding its your call. When the pax show up late, you decide when they go on. If the Captain wants weather, or a new flight plan, you're going to have to get it... or get someone else to get it. You are also the go-between for the airline. If the flight takes a delay, you need to explain it, and find the cause.
Then comes the daunting bit. You are also loadmaster to some extent. Although most airlines have standard policies, you are responsible for seeing them carried out. You are the one who has to account for every piece of baggage and every passenger. Its up to you to ensure the manifest is 100% accurate and that nothing is in that hold that shouldn't be, and that nothing is anywhere in the hold that it shouldn't be. If theres a load of firearms on board, its up to you to make sure all the paperwork is accurate. I'm not sure if servisair dispatchers compile the loadsheets, but if so, you will also be needed to understand and calculate the various weights and balances to ensure that the aircraft is safe to takeoff and land, and also to work out how much the aircraft is over/underloaded.
I hope that helps, and isnt too daunting. Dispatchers take a lot of the flack when things go wrong, but I would say are some of the most job happy people I have ever worked with.
Basically be prepared to use words like "co-ordination", "timekeeping", "working under pressure", "responsibility" and "security" in the interview, and remember that at times you are going to face some pressure and some stick. So being thickskinned helps. Standing up to a flight crew to tell them they need to take a delay while you re-load an aircraft, or telling them that you are recording the 25minute delay to them takes some doing.
RTG!