BlackBerry maker Research in Motion is taking on iPad in the table computer game with a "PlayBook" aimed to capitalise on its strength -- the trust of business users keen on secure communications.

"It is the world's first professional tablet," RIM president and co-chief executive Mike Lazaridis said as he showed off the device in San Francisco.

The PlayBook is one of a number of tablet computers slated for release in a bid to challenge Apple's popular iPad and is the first foray outside the mobile phone realm for the Waterloo, Ontario-based RIM.