A book on the big names in Big Business; The Rise and Fall of the Conglomerate Kings, by Robert Sobel. New York: Stein & Day. 240 pp. $19.95.

The new book by Robert Sobel, a professor and columnist, is a highly readable , meticulously researched history of the unusual, often idiosyncratic ''conglomerateurs'' who have brought spectacular financial pyrotechnics to post-World War II Wall Street.

This book is more entertaining than it is educational. It recounts the stories of several ambitious individuals rather than taking sides in the debate as to whether corporate mergers and takeovers are ''among the chief disgraces of capitalism'' or are ''part of the process of (economic) renewal.''

One of the chief virtues of this book is that the author evidently has no axes to grind against the individuals whose deeds he retells. Some of his subjects might not be pleased with the image that emerges of them in these pages , but the portraits seem to be firmly grounded on objective research.

If you are fascinated by the exploits, errors, and endeavors of the big names in Big Business, then this is a book for you.