Obviously this reply is a year late, but I found your post in a search so I figured if it doesn’t help you maybe it’ll help someone else eventually. You can import a CSV as a new table, so that should work just fine for you. Also, this blog post goes over all the ways you can work with calendars (import, export, and sync).

Hi Adam,

I’ve actually asked Support this same question. The goal is not to import a CSV as a new table, but to connect an existing calendar into an existing base.

The blog post I linked to goes over how to do that. Just go to the two-way sync section. You’ll need to use Zapier to create the sync. You just need to select the Outlook integration instead of Google Calendar. (I think that’s what I used as an example in that article but the instructions are virtually the same with any Zapier-supported calendar integration.) If you have trouble getting things set up, let me know what the issue is and I’ll try to help you sort it out. It’s helpful for me to know if certain things are difficult or confusing so I can focus on simplifying them when creating these guides.