Can iCal calendars be combined?

Had a little trouble when I tested this--I chose an untitled calendar with little data to test export/import. Export worked fine, but when I tried to Import I don't recall having a chance to select the calendar I wanted it imported into--it just started importing, and the progress bar has been going for a long time. Assuming I can work this out, here is a related question:

Is there an easy way to see what a particular calendar contains? Like a list view for its entire life span? I have been doing Year views, then selectively checking and unchecking calendars to see if anything changes. Very cumbersome. Also, what is a "Data File" calendar? I don't recall creating them.

Here's the Date File calendar. As I recall it was created spontaneously a long time ago--it was not a category I created by choice. I assumed it might be for such things as notes that I added at the bottom of some events (like what we had for dinner at a holiday event).

Thanks for the screenshot--it helped. Made it work the second time. I think the problem was that the calendar that I was testing it on did not contain any "new events."

Thanks also for the suggestion as to how to view old events in list form.

Thanks, Austin. With your help I have worked through most of this. Finally recognized the qdfm extension as Quicken–one of them was an old repeating event (reminder to make a loan payment) that may have been a Quicken feature that linked to iCal. Who knew?

Not showing on the pic above is the short On My Mac list (Home, Calendar, Work). Still not clear what their function is in this brave new iCloud world. Can I export/import into their iCloud counterparts? Or would that cause some kind of fatal feedback loop?