Hi Tom,
From Outlook you could go to File, Import and Export, Import from another file or program, Microsoft Access 97-2003.
However, I suggest that you don't do it that way.
Instead - from Access, link to the outlook contacts folder you want to interact with.
External Data, under the XML File click on the More button and you will see Outlook folder is an option. Do not import, make a link.
Now - you can create a query to select the records you wish to append to the linked table, make sure things look right, then create an append query to import the contents of that querry result recordset to your linked Outlook table. This gives you a chance to see what you are doing before you make big wampum oops to your existing contact data . You should probably figure out a key field and do something like
SELECT myQuery.*
FROM myQuery LEFT JOIN LinkedTable
ON myQuery.keyfield = linkedtable.keyfield
WHERE inkedtable.keyfield is Null;
This will only bring up rows of data from myQuery where a corresponding record in the LinkedTable doesn't already exist. This may help you to avoid massively duping your contact folder, an event that is not my idea of fun.
Hope this helps...
Gordon