Do not let tablets distract you from important activities. Using it can be a time sink.
It is proper Netiquette to share content with people around you. Do allow people to look at your screen.
It is good Netiquette to use it where appropriate. Don’t use it everywhere.
It is proper Netiquette to refrain from using them in public restrooms. Don’t use it in the bathroom at restaurants or coffee shops.
It is proper Netiquette to greet people in meetings before turning it on. Don’t ignore people your supposed to engage.