The full version of Outlook 2013 RT with touch-friend support is available for download from the Windows Store, but it is still lacks features like add-ins and Lync integration. If you have upgraded Surface RT to Windows 8.1 and also want to replace the build-in mail app, there are two options for migrating contacts which have been kept in the People app (Live.com).
Transfer/Move Contacts from People App to Outlook RT in Windows RT 8.1
Your microsoft Live account have been already stored everything
* Open Outlook app, Click File > Add Account.
* In the Auto Account Setup page, type the related information, including your name, email address and password. If you need to configure others, check “Manual setup or additional server types” box. Then click Next button to finish the process.
The contacts are stored in multiple accounts
* Open IE browser, login to Outlook.com or Live.com website by your own account.
* Pull down the arrow in top left corner next to the Logo icon, and select “People” square.
* In the top middle, click the arrow next to Manage, and choose “Export” from the menu.
* Safe and download the .csv file to your desktop.
* Import contacts from an Excel spreadsheet into Outlook by following the instructions.