A tablet is not just hardware, obviously, but also software. If you have not used webOS, you might not be aware of the significant differences between iOS and webOS, but they are
quite different. I had a Palm Pre for a few months (webOS) and I loved the clean multitasking and the card metaphor -- iOS has
nothing like this, so Palm/HP are hardly copying Apple on this. Also, the notification system on webOS runs circles around the toyish notification system of iOS -- which is the reason why I no longer use my iPhone 4 as my primary communications device and it is relegated to a mini iPad now, and I love it in that capacity.

Heck, even the ancient, aging Blackberry OS has a superior notification system to iOS.
Bottom line: the table physically has a
striking resemblance (but not identical when you see them side by side) but the tablet as a total product is anything BUT a "clone" of the iPad.