In a move calculated to take advantage of the marketing opportunities in the trend toward small computers and more advanced office technology, International Business Machines Corp. opened a spate of office products stores last week in major cities across the country, including Washington.

The local IBM store at 919 18th St. NW looks like nothing more than a futuristic version of the small-town typewriter store and repair shop. IBM Selectric typewriters, word processors with display screens for editing, transcribers, table-top copiers and computers are displayed attractively on desks with high-tech chairs, all inviting experimentation.

IBM says its 10 new office-product centers represent the company's attempt to market its wares to individuals and small businesses in a retail environment, in addition to sales through large company contracts. A 5 percent cash-and-carry discount is available.

The most popular item at the store is the IBM personal computer, according to Allen Gill, manager of IBM retail operations. The unit can be hooked up to a television or purchased with its own screen. It can perform a variety of tricks, including video games, in black and white or color, silently or to music.

"The new computers have generated a great deal of traffic," Gill said. "It attracts a range of customers. You'll find that there are offices in the home where the computer is also used as a game. But the home use is more secondary to its use in business."

Gill added that many of the customers interested in the personal computers "are very well informed. I think a lot of this is because of public education, which for the last 10 years has put emphasis on computers. Exposure to computers has increased as the prices have come down."

IBM began testing its product centers in Europe and Latin America several years ago, Gill said. Baltimore and Philadelphia had the first of 10 centers in this country. The company now has 18 product centers outside the United States.