A recent update for the Galaxy Note 10.1 made them fully compatible with the 64GB micro SD / SDXC cards. However, before you use them, we suggest formatting it before hand. Now, if you own a Mac, formatting is pretty much straight forward. You can use its disk utility to format the card.
However, things are not so straight forward if you are a Windows user – like me. To format it, go to start > Run and type in cmd. Then type Format /fs:FAT32 driveletter: where driveletter is the name of your drive. Once you confirm the operation you will see information stating what the current Filesystem is and that it will be changed to FAT32. It will format the card and then verify it which will probably a while – it took nearly five minutes to verify a 2Gb Sd Card. Once done it will ask you for a Volume Name, just press ENTER for NONE. You will then be given a report. Type EXIT, press ENTER and remove your card.
That is it. Your 64GB micro SD card is ready to be used with your Galaxy note 10.1 tablet. You can buy one for cheap from Amazon, mere 60 dollars.