What technologies are used to develop games for tablets and iPhones?
Would Flash be commonly used?
Is HTML5 capable of animation and interactivity, or would a game file simply be placed within HTML5 code?
Is Flash and HTML5, and then wrapping the game for different phone/tablet operating systems a common combination?
Flash isn't very common (at least when it comes to games) because of performance concerns.
No, because Flash content doesn't run on iOS and Adobe discontinued development of their mobile flash player. With Adobe Flash CS5.5 or Flex Builder 4.5 you can export your AIR app as native app for iOS, Android or Blackberry though.
iOS devices such as iPhones and iPads don't support Flash at all. There are a few HTML5-based games, s HTML5 is capable of animation and interactivity. You might want to look at OpenGL.