Something tantalizing is tempting: like a meal that smells amazing and makes you want to eat it. Tantalizing things are very appealing.
When something is tantalizing, it makes you want it, even if it's totally out of reach. An exciting movie trailer could be tantalizing if it makes you want to see the movie. A little part of a song can be tantalizing if it tempts you to hear more. Smells — when they're good smells — can be very tantalizing. Just walking through a good restaurant, smelling and looking at the food, is a tantalizing experience.