Internal memory is important for a tablet, as that is used to store the operating system and at least part of every app. By increasing the amount of storage available using a memory card slot, the internal memory can be kept free for what really needs to use it, whilst an external memory card can be used to store user-created material, such as videos and photos taken using the camera, and downloaded content.
The Sannuo 10.1″ Kids Tablet does have a memory card slot and will take SD cards up to 128 gigabytes (GB). Most children’s tablets still only take memory cards significantly smaller than that, with 32 GB being perhaps the most common capacity still.