Yes. Create a new PST with File>New>Outlook Data File. Right-click your
Calendar and select Copy. SPecify the new PST as the destination. When the
copy completes, right-click the new PST and choose Close. Close Outlook.
Rename the file type of the PST you created to .psx or something . Start
Outlook. Create a new message and attach the renamed PST. Send the
message.
When the recipient receives it, s/he should save it to disk, rename its file
type to .pst, and then open it in Outlook with FIle>Open>Outlook Data File.
The contents of the Calendar folder you put in it will now be available to
the recipient.