Outlook stores phone numbers. It does not manage phone calls for you. You
would use a telephone for that. If for some reason you wanted your computer
to do that for you, you would purchase a voice modem and appropriate
software.
Outlook can place a call if you want it to, but it only invokes the Windows
dialer to do so. You must still have a telephone handset plugged into your
modem if you wanted to do such things as talk to the person you dialed.