Good evening Mike and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
We are sorry to hear about the iCal importer going way overboard with it’s import!
I would love to try to help you with this topic.
I am unsure exactly why this is happening in your case, but I would be very interested in replicating it in order to find the cause.
As a first troubleshooting step, could you please provide us with your system information in a private reply ? (following the instructions found in the link)
Also, if you don’t mind, could you share with me the iCal URL you are trying to import from ?
Best regards,
Geoff B.