Here below are mentioned the most popular tablets and their screen sizes.
Kindle Fire - 7 inches and 8.9 inches
Google Nexus - 7 inches and 10 inches
iPad Mini and iPad - 7.9 inches and 9.7 inches
Samsung Galaxy Tab - 7 inches and 10.1 inches
ASUS Transformer - 10.1 inches
Microsoft Surface - 10.6 inches
Samsung Series 7 Slate - 11.6 inches