Current versions have limited import/export capabilities via the now ancient "PMIMPORT" DOS utility still provided with the program. V5 will support import/export in a variety of formats, including CSV, TSV and Vcard.

Cheers!

-- David --

Is there a way to import and export address book entries?

You can import and export address books by choosing the address book entry from the addresses menu.  When that pane has the focus, you'll see and addressbook menu in the menu bar, which will give choices for importing and exporting.