Google has recently shared some SEO tips for building a search engine friendly mobile tablet experience for users as well as search engines. Google has pointed out these are tips NOT specific “recommendations for building search engine friendly tablet-optimized websites.” Google does at time of writing have guidelines or official recommendations for tablet-optimised web sites but they do now offer some tips based on their official recommendation for smartphone optimised sites: http://googlewebmastercentral.blogspot.co.uk/2012/06/recommendations-for-building-smartphone.html .
The optimisation tips for tablet devices include:
(1) Unless you offer content specifically optimised for tablets, tablet device users will expect to see your 'normal' desktop site rather than your site’s content optimised for smartphones .
(2) When offering content for tablet devices, use responsive design and test designs on multiple tablet devices.
(3) If you are doing redirects, ensure that you don't redirect tablet users to the site optimised for smartphones too.
(4) Google lists on http://googlewebmastercentral.blogspot.com/2012/11/giving-tablet-users-full-sized-web.html how you can tell Android phones and tablet devices apart using user-agents.