How to Add Friends in Skype.

1. 

   It's easy to add a Skype contact:

   1. Sign in to Skype.
   2. Tap the more button at the top-right of the screen.
   3. Select Add people.
   4. Enter a contact's name, Skype Name or email address.
   5. Select a contact from the list of results and tap Add to contacts.
   6. Edit the contact request message if you like (by tapping Edit) and tap Send.

   Source: https://support.skype.com/en/faq/FA12151/adding-contacts-android-tablets