Thank you for using The Events Calendar, I can help you with this!
Oftentimes, as you add new plugins to your website, they add columns to your posts/events tables. That appears to be what has happened in your case here.
You can fix this by going to the ‘Screen Options’ tab at the very top of the page and unchecking any unnecessary columns. See the screenshot for clarification.
I hope this helps, let me know if you need anything else!