Meaty fiction with a draft of sadness; Dinner at the Homesick Restaurant, by Anne Tyler. New York: Alfred A. Knopf. 303 pp. $13.50.

Despite the pervading gloom of Anne Tyler's ninth novel, it is a joy to read in much the same way that any beautifully written tragedy is not just for entertainment, but for enlightenment, too.

The story takes place as Pearl Tull is visited by her children for the last time. As we walk down memory lane with Pearl, and then in turn with each of her three children, we see that we're always on the shady side of the street.

Their lives have been colored by a single, shared event - the husband's desertion of them all. They can't forgive him, nor can they forgive one another's shortcomings.

There are a number of references to illness - illnesses that are used to show that the Tulls dread life more than death.Pearl has been going blind for several years - which suggests that she looked at life through a glass darkly.

As the children gather for dinner after the funeral, we see that they have always been homesick - sick of home, and yet yearning for a home. Ezra, the youngest and the apple of his mother's eye, owns the Homesick Restaurant where he dishes up ''consoling pot roast'' and stews ''made with love.'' But at this meal, as at all the family reunions, the food is left unfinished, and each of the family members leaves the table unfulfilled once again.

Miss Tyler's latest book perched briefly on the best-seller list, then slid quickly off. This book is not the stuff that best sellers are made of. But if you prefer substance to fluff, although served with a deep draft of sadness, then ''Dinner at the Homesick Restaurant'' could be your fare.