Anything is possible!
If you don’t want to place those images in the description though you’d need to get creative: there might be some existing plugins out there you can re-purpose and I seem to remember there is one that even lets you add multiple featured images to posts, including (I believe) custom post types such as events.
Combine something like that with a template override (you might customize the single-event.php template and replace the tribe_event_featured_image() call with some new function that takes a stack of featured images and transforms them into a gallery/slideshow, for instance) and you should be able to get there.
You can find out more about template overrides and safe customization of The Events Calendar/Events Calendar PRO in our Themer’s Guide:
tri.be/support/documentation/events-calendar-themers-guide
I hope that helps 🙂