Out2Mac works very well in moving mails, contacts and calendar to Entourage 2008 version on Mac. Howver, the Calendar instructions don't work in Entourage which is part of Office Professional 2008.
In this case, Highlight all items in the Cal Folder (individual files) and double click the files with Entourage running. This then individually adds the calendar entries into Entourage.
Regretably, you then have to
Close a slew of open windows (over 2000 in my case). I did not try with a single export file which might have accomplished the same thing.
Entourage 2008 says NOTHING about importing into calendar at all. It does say there is no possible link between ICAl and Calendar in Entourage. It is silent on the method I have used.
Hope this helps in future.
By the way, the total file size I transferred was 3.76 GB including all archives. It took over 2 days to create on Out2Mac but did work perfectly.