Ooops I did not yet directly answer your question. You could delete all events by going going directly into the back end database, possibly through PHP My Admin, and deleting events with tribe_events post type. You would also want to delete their post meta. This is a very sticky process, but is pretty much your only options when your server is hitting fatal errors on the front end. It’s also very dangerous, even if you know WP databases very well. The best route is definitely to look into upping your memory limit, and thus removing the error from the front end without deleting any events.
– Brook