In Tools…Addressbook you may have to pick from a list that looks like this:

Outlook Address Book
Contacts
Contacts
.
.
.
Where only the last one has any contacts.
The way to remove this condition is to go to
TOOLS | EMAIL ACCOUNTS | DIRECTORIES | “View or Change…”.
Select your Outlook Book service, than change. On the next page, delete the empty Address Books entries.
After restart Outlook they should be gone.

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