This is a reply received from Corel Customer Services after finding EVENT Files in certain folders:
Thank you for your e-mail. Please be advised that .event file is a hidden file and is automatically created once a folder in your hard drive has been cataloged by Corel Digital Studio, PaintShop Photo Express, etc. Corel Digital Studio creates a thumbnails of the images stored in a folder and the .event file monitors the changes inside that folder (removing and adding photos, etc.). When Corel Digital Studio is installed on your computer, the .event file will be added to each folder with stored media files in it.
Regards, Allan Corel Customer Service
(it isn't related to the Windows Event Viewer)