I have two unknown entries in my Humble Bundle library. I purchased both Alan Wake games from Humble Store and activated the keys on Steam, I doubt additional copies are provided.
Please note that gifting option (an icon next to DS 2) isn't available for either game.
It basically means that currently the game that you have activated in your Steam account is a region restricted copy. However as Humble Bundle provides WW releases so they have given you the option to activate them in case you move to some other continent. In that case those two entries you have in your library won't be there because you won't be able to run them. At that time you can add these and play.
Also if you want those WW releases in your account then you can try adding them to your library, if they don't get added you can always ask Steam support and they'll most probably tell you to remove the games permanently and then add new keys to your account.