For you, Thanksgiving probably has receded into distant memory by now. For Peter Arcaro of Wheaton, it couldn't.

Peter had a Thanksgiving this year that well may deserve a niche in the Guinness Book of World Records. When he pulled back his chair and said, "Let's eat," 51 of his relatives took him up on it.

A mere 52 for Thanksgiving dinner! Peter's probably still doing the dishes. Just the thought of all that food heaped onto two tables makes me hungry all over again.

Peter's nephew, Ralph Chite, believes it was the largest gathering to have been held in a private home in the Washington area that day. Who could disagree?

The tradition of massive family Thanksgivings was started in Peter's house when his mother, Michelina Arcaro, moved there in 1955.

Michelina was born in Italy, and she liked to merge the traditions of old country and new. As a result, turkey always was on the Thanksgiving menu, but so were lasagna, ravioli and a lot of other Italian goodies the Pilgrims never heard of.

When Michelina died in 1970, the family continued to serve pasta each Thanksgiving -- until this one. For the first time, Ralph reports, this year's feast was strictly Norman Rockwell: turkey, stuffing, cranberry sauce and sweet potatoes. The lasagna was left out "because the family wanted to be more traditional."

Still, two turkeys (a 30-pounder and a 25-pound "little brother") were nothing to sneeze at. Neither were the home movies of past Turkey Days that Peter showed for dessert.

Doing it again next year, in the house on Newport Mill Road? "But of course," says Ralph.

Who were the 52 who showed up? They were Michelina's nine children, 25 of her 30 grandchildren and her seven greatgrandchildren. The other 11 were spouses.

And if you can stand this, 52 wasn't a family record. "Had 55 just last year," says Ralph. Peter's probably still doing the dishes from that one, too.

More of the personal touch from that modern marvel, Monsieur Le Computer.

Grace L. Schoner of Vienna mailed in an advertising brochure she received recently from The Hecht Co.

The second line of the address label reads, "HECHTS SPECIAL CUSTOMER."

The rest of it reads, "BOXHOLDER, RFD 7, VIENNA, VA 22180." Grace is such a special customer that her name isn't mentioned anywhere.

"Let me be honest with you," said the slightly raspy voice on the other end of the phone. "It's just another day."

But nothing could be further from the truth. On Dec. 4, Johnny Di Joseph celebrated his 50th anniversary as owner, manager, photographer, chief cook and bottlewasher for Reni Newsphoto Inc., a photography service located at 805 G St. NW.

Since 1932, Johnny Di Joseph has photographed "every President since Coolidge, three Popes and a whole lot of people who weren't as good as any of them." He also has trained about a dozen photographers who are still plying their trade for newspapers and wire services here.

In the old days, much of Di Joseph's work was done for local papers and wire services that were short on photographers. Lately, most of Reni's clients have been religious and trade publications. "It's not what it used to be," says Johnny. "I don't have to tell you. The news photo business has been turned on its head by TV."

Still, staying afloat for 50 years means a guy must be doing something right, particularly in a city like this one, which is so tough on small businessmen.

"Yeah, it's a milestone, I guess," Di Joseph said. "And I guess I'll keep on as long as I'm able to carry on. What else am I going to do?"

Well, you could come out of the darkroom for a minute and accept the congratulations of the news capital of the world, Johnny. You deserve them. CHILDREN'S HOSPITAL

The parents never, ever forget.

"As promised last year," writes Richard Joseph of Silver Spring, "the enclosed check for $14 is in appreciation for my son's 14th birthday.

"If you recall, I sent a check for $13 last year and mentioned as an infant, my son was treated at the old Children's Hospital for suspected seizures. Thanks be to the Almighty and the wonderful care he received at Children's when he was just a baby, he is continuing to develop into a fine, healthy lad, now over six feet tall. He's a pretty good basketball player, too!

" Signed Proud Papa."

I'll be looking for that $15 check next year, P.P. Many thanks.

"In November, 1976, our four-month-old daughter was operated on at Children's Hospital," writes Nancy Price of Burke.

"Today she is in first grade, doesn't sing in music class, keeps a messy desk -- but she is so healthy and happy.

"We are always grateful for Children's Hospital. Thank you."

Don't thank me, Nancy. You know who deserves the thanks.

Sometimes Children's is the last chance -- and very often it comes through. Listen to the story of Linda Grise of Springfield:

At the age of three, the daughter of a friend of hers "inexplicably withdrew into a shell no one could penetrate . . . . By the age of six, she could not or would not communicate, interact, nor even control her bodily functions. Countless doctors, psychologists, special ed teachers etc. finally gave up and encouraged her parents to have her institutionalized 'for the good of the whole family.'

"You can never know the anguish this recommendation caused. Then someone suggested trying Children's Hospital.

" . . . Therapy was a long, slow process--beginning in the old facility and ending in the new. Today, Bob, this child whom so many were ready to give up on is a truly beautiful, bright, healthy, happy, confident 12-year-old with a marvelous, mischievous sense of humor . . . . If it were not for the love and caring of countless doctors, social workers and aides at Children's, life today would be unspeakably bleak for this whole family."

If you're surprised by this, you shouldn't be. For Children's Hospital performs this sort of turnaround every day.

Won't you make a donation so that it can continue?