Don't but the 64 GB Surface Pro tablet. Buy 128 GB version instead!
Windows 8 Pro operating system and the pre-installed software Microsoft Surface Pro eat up approximately 45 GB of SSD storage space. It means if you buy 64 GB version of Surface Pro, you will get only 16 GB of storage space in your tablet. And if you buy 128 GB version of Surface Pro then you will get 83 GB space.
If you are going to buy a Surface RT tablet then you should keep this in mind that 32 GB Surface with Windows RT also offers only 16 GB of storage available for user content. 64 GB version of Surface RT provides 45 GB of storage space.