Research in Motion showed off the tablet for the first time overnight and is set to launch it early 2011, with an international rollout later in the year.With it, RIM is betting on a smaller, lighter device than Apple's iPad, which kickstarted the tablet market when it launched in April.
The PlayBook will have a 7-inch screen, compared to the iPad's 9.7 inches, and weigh 400g compared to the iPad's 700g.
And unlike the iPad, it will have two cameras, front and back.
RIM didn't say what it would cost, but said it would be in the same range as the iPad, which starts at $629.
The PlayBook will be able to act as a second, larger screen for a BlackBerry phone, through a secure short-range wireless link.
When the connection is severed - perhaps because the user walks away with the phone - no sensitive data like company emails are left on the tablet.
Outside of Wi-Fi range, it will be able to access the web by linking to a BlackBerry.
But the tablet will also work as a standalone device. RIM co-chief executive Jim Balsillie said its goal was to present the full web experience of a computer, including the ability to display Flash video and interactive material on the web.
That means the tablet will be less dependent on third-party applications, Mr Balsillie said.
"I don't need to download a YouTube app if I've got YouTube on the web," he said.
Apple CEO Steve Jobs has resisted allowing Flash on any of the company's mobile gadgets, arguing the software has too many bugs and sucks too much battery life.
"Much of the market has been defined in terms of how you fit the web to mobility," Mr Balsillie said.
"What we're launching is really the first mobile product that is designed to give full web fidelity."
In part, the PlayBook is a move by RIM to protect its position as the top provider of mobile gadgets for the business set.
Mr Balsillie says he has had briefings with company chief information officers and "this is hands-down, slam-dunk what they're looking for".
Analysts agree that RIM's close relationship with its corporate clients could help the company establish a comfortable niche in the tablet market despite Apple's early lead.
RIM is using a new operating system, built by QNX Software Systems, which it took over earlier this year, to harness the power of the tablet, but Mr Balsillie said it will run existing apps for BlackBerry phones.
IDC predicts that the corporate market for tablet computers will grow as a portion of overall sales over the next few years.
The firm forecasts that roughly 11 per cent of overall tablet shipments, or 6.5 million units, will be to businesses, government agencies or schools by 2014.
That would be up from just two per cent, or 300,000 units, this year. And that figure doesn't count those who buy tablet computers on their own and use them for work.
RIM doesn't want the PlayBook to be just for work - the company invited video game maker Electronic Arts to help introduce the PlayBook at the launch event in San Francisco - but it's clear that its advantages will lie in the work arena.
Amazon announced it would make its Kindle e-book reading software available for the tablet.
The iPad has prompted a wave of competitors.
Dell came out with its own tablet computer in August called the Streak.
Samsung plans to launch the Galaxy Tab next month and has already lined up all four major US carriers to sell it and provide wireless service for it.