Asus is shipping the tablet with a dock accessory. Buyers cannot purchase the tablet without the dock accessory, a company spokeswoman said. Exclusion of the dock could have cut the entry price, but buyers will now have to shell out $599 for the Vivo Tab RT.

Asus is offering an optional keyboard dock with a built-in spare battery for $199, which could bring the overall purchase price of Vivo Tab RT to $798. With an add-on keyboard, Microsoft's Surface tablet with 32GB of storage is priced at $599.

The key figure with Windows RT tablets is Microsoft and Dell's entry price of $499, and any tablet with a higher entry price is less likely to succeed, said senior analyst Sarah Rotman Epps of Forrester Research.

The Vivo Tab RT, which was originally called Tablet 600, was the first device to be shown with Windows RT. The tablet has a 10.1-inch screen and shows images at a 1280-by-800 pixel resolution.

The tablet weighs 520 grams, making it lighter than other Windows RT tablets including Microsoft's Surface and Dell's XPS 10. It is 8.35 millimeters thick.