In Base I'm able to connect to the Mac Address Book. 

To integrate the address book:
1) Select file->Wizards->Address Data Source...
2) You should see an option called "Mac OS X Address Book" - select it and
click "Next."
3) If you have any groups in your address book, you'll see a screen for
selecting your main table with "Address Book" followed by all of your
groups. I usually select "Address Book."
4) Rename the data source if you want to, and click "Finish."
5) View your data sources. You can do this in many ways: press F4, click on
the "Data Sources" icon in the toolbar, or select: View->Data Sources.

Now, you should see the address book as the data source you just added. (For
me, the aqua build opens it automatically, while the X11 build only shows
the data source's name ("Addresses," unless you renamed it in step 4), and
you have to expand it, and then expand "Tables" to see the available tables
in the data source, including "Address Book," and all of your groups.)


These instructions are copied from here:
http://porting.openoffice.org/servlets/ReadMsg?listName=mac&msgNo=5680


Its not possible to change anything in the Address Book using Base. Only
read-only access is supported. Items that allow you to change data in the table
are ghosted (menu items and icons in the toolbar) or do not invoke the requested
change (like delete row in the context menu when you right click on a row).

I would like to request the feature that enables me to also write in the Address
Book via Base.

I read that other address book implementations also don't support this (outlook
express and thunderbird where mentioned if I recall correctly). So this might
mean that this feature request involves more then just a 'porting' issue.