A tablet is not a stretched-out mobile device. The kinds of interaction that tend to be fun within the tablet environment focus around drawing, multi-touch and direct manipulation of on-screen elements, whereas mobile is more about selecting and tilting. Tablets are also more comfortable to use in landscape mode than portrait (mobile is the reverse), and have more concentrated use-cases: In mobile gaming an individual game session should fit within the period of time spent waiting for a bus, but tablets are often used for sit-down-and-play sessions.
...
The fluidity of interaction with a tablet is also different to mobile. Smartphones are organised around holding the device in one hand and using the thumb on that same hand to interact. However tablets are either fully held in one hand and interacted with by index finger, or sit in a stand and accept multiple finger input. As I type this article, the screen is within reach. I often reach up to select, move the cursor, cut or copy text – and that happens with much less intermediation than a laptop touchpad.
...
Understanding that tablet is more than just stretched-out mobile leads to all sorts of interesting design challenges.