At Apple, a tablet-like device has been many years in the making. Apple filed a patent related to a tablet device as early as 2000, according to a Thomson Reuters patent database. But development has come in fits and starts. Mr. Jobs killed the project twice in recent years, the first time because the battery life was too short, and the second time because there was insufficient memory, said one of the people familiar with the matter.

Though Apple doesn't discuss future products, many analysts expect its tablet to be a multimedia device that will let people watch movies and television shows, play games, surf the Internet and potentially read electronic books and newspapers. It is not clear whether the device will run the full Macintosh operating system or a version of the iPhone operating system. Apple watchers expect the tablet to debut at the end of this year or early next year.

Analysts say how well an Apple tablet sells will depend on price, which most believe will be between $399, the price of a high-end iPod touch, and $999, the price of the cheapest MacBook laptop. "As devices become more expensive, your ability to make them mass market declines," said Toni Sacconaghi, an analyst with Sanford C. Bernstein & Co.

The popularity of cheap and light computers under $500 known as netbooks has pressured Apple to come out with a device in a similar price range. But as recently as last October, Mr. Jobs rejected the idea of a cheaper computer in an earnings call, saying, "We don't know how to make a $500 computer that's not a piece of junk."