The most important part of the memory for any tablet is the internal memory, as there are many items that cannot be transferred to external storage, such as the operating system and many apps.
However, external storage does still have its uses. The primary use is for storing user created content, especially such as photos and videos. As the resolution of tablet cameras increases, so does the amount of space the resulting files take up. Downloaded material such as ebook and videos can also be stored externally.
It is for such that a memory card slot is useful. This allows content to be stored on a micro SD card, so that such content doesn’t take up important internal storage. The nabi DreamTab comes with a microSD card slot that will take memory cards up to 32 gigabytes in size.