All about how the mutual funds performed -- in 700 pages of detail

It's about the size of one of those coffeetable books people give each other for Christmas, the kind most people do not read; they just look at the pictures.

But this one has no pictures. Still, this bookshelf-bending tome is carefully read by the 4,000 to 5,000 mutual fund buffs who depend on it for general information, charts, graphs, addresses, and articles about the mutual fund industry in general and many of the funds in particular.

It's put out by Wiesenberger Investment Companies Service and titled simply Investment Companies. Its title page fairly accurately describes its mission:

''An annual compendium of information about Mutual Funds and Investment Companies . . . a complete explanation of their functions and their various uses to the investor . . . data on the background, management policy and salient features of all leading companies . . . management results, income and dividends records, price ranges and comparative operating details.''

Over the years, says editor Paul A. Johnston, filling that assignment has meant that the book has grown in size and scope as the industry it covers has grown. This year's edition is almost twice as large as the one Mr. Johnston helped put out when he joined Wiesenberger 12 years ago.

In recent years this growth has meant that the book was coming out later every year. This disturbing trend continued through last year, Mr. Johnston said , when the first copies of the book did not come out until September and some were sent as late as October.

If allowed to continue, this trend could have made the book - which is supposed to be a record of the previous year's mutual fund activity - a record of mutual fund activity two years ago.

But this year ''the publisher (Warren, Gorham & Lamont Inc.) read the riot act to us to get it out early,'' Mr. Johnston said. ''So everybody pushed and we got it out earlier than ever.'' The first copies came out in July.

The main problem in publishing a 709-page book like this in six months, the editor said, is getting the mutual funds to send back the questionnaires they received from Wiesenberger in January. Normally, he noted, he would like to get them back in February or March. But that is the time funds personnel are filling out a lot of other things, like tax forms. In addition, there are several other mutual fund newsletters and book publishers that want information. The questions are often different, so a standard response won't do.

While the book contains a great deal of overall information and statistics on mutual funds in general, its strength is in some 550 pages of articles, statistics, and addresses on individual funds. Much of the information is from prospectuses, but it also includes 10 years of statistical history on each fund.

Mutual funds aren't the only buyers of this book on themselves, Mr. Johnston says. It is also purchased by brokerages, insurance companies, and libraries. But not many individuals buy it, he admits. The book is part of a package that includes monthly and quarterly newsletters. The package sells for $195 a year.

For those not scared off by the price or by a book that weighs nearly six pounds, the address is: Wiesenberger Financial Services, Warren, Gorham & Lamont Inc., 1633 Broadway, New York, N.Y. 10019.