Hi
The file size limit is not handled by Event Booking. It is a setting of your server (usually, server only allows you upload file smaller than 2MB). If you want to upload large file, you can use two options below :
1. You can contact your hosting provider to change the max upload file size setting to 10MB (or larger) .
2. You can upload files via FTP (no file size limit in this case) .
Regards,
Tuan