Hours: Lunch, 11:30 a.m. to 2:30 p.m. Tuesdays through Fridays; Dinner, 6 p.m. to 10:30 p.m. Tuesdays through Saturdays; 4 p.m. to 10:30 p.m., Sundays. Sunday brunch, noon to 2:30 p.m.

Atmosphere: Warm, serene and informal; children not just tolerated but welcomed.

Price range: Dinner entrees in the $6 and $7 range; lunch main dishes, $2 to $5, and brunch entrees $2 to $4. Children's portions, half price.

Special facilities: Non-smokers room: high chairs; accessible to the handicapped; parking lot. Live music on Sunday evenings, usually madrigal singers, a classical guitarist or pianist. Poetry readings.

Reservations: Accepted only for parties of six or larger.

Credit cards: None accepted.

It was like going to the home of a friend, and one who knows her way around the kitchen. Mrs. Z's place up in Columbia, where we had brunch, has a natural informality that allows children to toast marshmallows in the fireplace while the grown-ups linger unharrassed over the Sunday papers and another cup of coffee.

For us, Mrs. Z's is the Taj Mahal of family restaurants. For one thing, the food, right down to the jams andsalad dressings, is made from scratch (no preservatives) and much of it has a classy international touch. For another, the prices are agreeable. And last, generations can mix it up here in easy comfort because Mrs. Z's has set a tone that appeals to almost everbody.

The interior of Mrs. Z's is a stark contrst to the outside, a boxy building surrounded by asphalt in the middle of Columbia's treeless landscape. Inside, the floors are carpeted, crafts for sale are casually displayed and the furniture is a pleasing mixture of antiques and old things picked up on treks through the Pennsylvania Amish country. The place is bereft of chrome and plastic - even the high chairs are wooden. The tables are set with basket-weave mats and gingham napkins.

Mrs. Z herself is a displaced Washingtonian who opened her restaurant (a term she dislikes - she likes to think of its a place where people can "just be together") four years ago. Aside from being a first-rate cook, she is a musician, which explains why there is a grand piano with dogeared sheet music in the dining room. Customers can, and do, play piano.

For small fry, who somehow always finish or quit eating before their elders, a corner full of toys is supplied. For senior citizens, a 15 percent discount is granted on Sundays for brunch and dinner, and Mrs. Z insisted that ramps be installed for persons in wheelchairs and for the elderly.

The procedure for getting your food is that you wander over to a counter, read the menu board and place your order. Simply, right? Wrong. Because lined up on this counter are little baskets filled with homemade bread - orange nut, honey wheat, cheese, apple. And while you are lathering the slices of bread with plain or honey butter from ceramic crocks, your concentration is killed, and so is your appetite, if you're not careful.

Anyway, the brunch menu offers onion or cream of spinach soup for $1.25. They had only half a bowl of the spinach soup left the day we were there, which was given to us free so we could "just taste it." We're glad we did - it was a concoction of stock and cream, chopped - not pured - spinach, a bit of onion and garlic - superb.

We passed up a glorious Greek salad, $3.95, made with lots of Feta cheese, anchovies, fressh herbs and all those good things. Even the lowly tuna fish sandwich on white bread (homemade, of course) looked appetizing.

Out 8-year-old and her buddy finally chose frisbee-sized blueberry pan cakes, $1.85; a side order of sausage, 85 cents,a nd cocoa, 50 cents. They finished this off with 60-cent pieces of chocolate cake, also set out on the counter in that mine field of goodies.

Once we retrieved our fists from the bread baskets, my husband and I rodered omelets, $2.95, his with onions, mine with cheese. (A chicken lever omelet is offered at $3.95, as is chicken liver and mushroom dish with wine or sour cream.)

While my husband indulged in a grand and gloppy chocolate ice cream cake for $1.50, I martyred myself by only having another slice of orange nut bread.

Meanwhile, the girls took off for the playground next to Mrs. Z's and we moved to comfortable chairs near the fireplace to refuel with more coffee.

Lunch and dinner is served at Mrs. Z's and the menu varies with the seasons and with the fresh produce and seafood available locally. In the ecumenical spirit, entrees include Greek moussaka, chicken teriyaki, chicken florentine and beef extraordinaire. Fish, shrimp and scallops are cooked in a variety of dishes.

The lunch bunch can get sandwiches, salads, cheese puffs, quiches, chilli or soups. Items at all meals are a la carte. No alcoholic beverages are served, but you can bring your own wine.

Our bill came to $20.40 (the girls did not have the children's portions at half price). Although the service is partially do-it-yourself, we left a $3.50 tip for the gracious assistance we did receive.