Can I watch Apple TV from my iPad?

No, you cannot watch Apple TV on an iPad. The Apple TV will only send its output via HDMI to the television it is connected to.

Most if not all of the content available on an Apple TV can be viewed on your iPad, though, either via Home Sharing from iTunes on your computer, downloading your purchases from the iTunes Store to the iPad, or via third-party apps for services other than the iTunes Store.

Regards.