YOu can use an SD card for additional storage. I don't know if there is a limit to the size of the SD Card. I did try a 16 Gigbyte card with my pictures and it worked. But it may be more a matter of the speed of transfer than the size of the card as there is only 2 gigbyte ram. I hope this helps.
The card slot is for a microSD. I keep a 64 GB one in mine. Works like any drive, and either media files or executables can be installed on it. However, Windows 8 considers the card temporary storage and won't let you add folders on the card to its "libraries." That's more a nuisance than a real problem for me.