First off, a minor matter of terminology. In Premiere Pro, "rendering" typically refers to processing all or part of a timeline to yield smoother playback. I gather that what you're speaking of is exporting, also known as encoding.
Premiere and Adobe Media Encoder have about 50 presets tailored to encoding video for playback on tablets. Finding them through the Export Settings dialog can be a drag, so I recommend using AME's Preset Browser, which allows you to filter the whole preset library down to those of interest. In your case, search for "tablet" or perhaps "iPad." For more info about the power of AME's Preset Browser, see post #2 here: http://forums.adobe.com/message/5950546#5950546