The best contact list is created by the user themselves, but sometimes customers ask for a pre-populated Lync contact list.
The only fully by Microsoft supported solution uses the team members from AD and adds them as contacts to a user’s contact list with “Set-CsPrivacyConfiguration -Identity Global -AutoInitiateContact $True”, http://support.microsoft.com/kb/2801016.
You can also use Exchange Distributions Groups whose membership will be automatically updated in Lync, but you still need to manually add the Distribution Groups.
If you need to add other contacts then there are possibilities, but they are not supported by Microsoft.
All user data is stored in a database. That data can be exported to a .xml file (using Export-CsUserData ), edited and imported again. You could also script that, or you could use tools such as Import Contacts, Contact Migrator, Add-CSContacts. or the Lync User Management Tool (LUMT).
And there are also third party solutions such as Xstran.