While President Carter was busy eliminating trimmings for the first state visit of his administration, Mrs. Jose Lopez Portillo, the wife of his visitor, the President of Mexico, was busy adding glitter.

From the arrival ceremony on the White House South Lawn yesterday, President Carter had eliminated: 14 hearld trumpets, blasting for attention from the White House balcony; 56 state and territorial flags and 56 servicemen to hold them smartly at attention, and a whole set of either Army Fife and Drum Corps, or Marine Drum and Bugle Corps, marching in review.

He also cut out his own musical accompaniment. President and Mrs. Carter walked in silence, hand in hand, from the White House to the review stand with the help of "Hail to the Chief." And they had no "Ruffles and lorishes" for themselves, although they kept a "Ruffles and Florishes", for the Mexican president and his wife.

So the most dazzling show of the day turn out to be when Mrs. Lopez Portillo produced her jewelry box at a luncheon in her honor given by the wife of the Secretary of State, Mrs. Cyrus Vance, and began displaying the crowded contents to the guests.

The Mexican First Lady appeared at the Musuem of History and Technology for the luncheon in a blue dress, the asynmetrical neckline of which was held together by a safety pin, and with a huge green necklace and matching drop earrings. But at dessert time, she summoned a military aide, who brought her a four-tierred red lacquered jewel box, which she inlocked at the table, and began rummaging through.

Her luggage from Mexico had not arrive at Blair House when it was time to change for the luncheon, she explained, and she was forced to choose a dress and jewels from among those she had with her in Williamsburg over the weekend. When the jewels did arrive, they were instantly taken to her, and she changed - in view of the guests - into an enormous gold-and-diamond butterfly brooch (which covered the safety pin) and the matching drop earrings and bracelets.

By the time she was selecting several rings to wear, the guests were spellbound, and she graciously acknowledged their curiosity by passing around the table the gold and diamond rings, magnetized so that the individual parts of them spin before your eyes.

The Piece de resistance was a peanut ring, which she explained was a companion piece to the ring she had given Mrs. Carter that morning, making it now the property of the people of the United States.

Mrs. Lopez Portillo designs her own jewelry, and the peanut ring consisted of two hearts topped by a button of small diamonds. The two hearts represents Mexico and the United States, she explained, and the two peanuts represented her and Mrs. Carter.

However, on the ring she gave Mrs. Carter, one peanut was much larger than the other. This was , she also explained, because the large peanut represented President Carter, while the smaller peanut stood for his wife.

After Mrs. Lopez Portillo had collected her jewelry back from the guests and adorned herself, she locked her jewelry case and the military aide took it away. However, she had more instructions for him, and she returned with her fur coat.

While her heart-shaped [WORD ILLEGIBLE] meringue remained half-eaten, Mrs. Lopez Portillo pulled apart the seam inside her fur, put her hand inside and extracted something the guests could not see. She returned the coat to the aide and questions about the gesture were shrugged off by the Mexican party.

While all this was going on, the Mexican President was the guest of the Secretary of State at a luncheon in the Department of State, which was described as a "working luncheon" with no such excitement.

Later, at the White House, pianist Rudolf Serkin, 73, rehearsed cautiously in the East Room for his appearance later, after dinner. He checked his pocket watch from time to time, because he did not want to have "too much noise here," not because he had been asked to keep his program short, he said.

Serkin said he had never met the Carters before and last appeared at the White House during the Nixon administration at the dinner of artist Andrew Wyeth. His first White House appearance was under the Johnson administration at the dinner for the President of Israel.

Serkins, who said his programs would include works of Mendelssohn and Beethoven, brought along his own piano - "I usually bring my piano because I'm not used to any other" - and ran through a selection of music just to "check the piano."

At the other end of the Great Hall, in the state dining room, Rosalyn Carter found herself suddenly conducting an impromptu press conference when reporters gathering to view the table settings encountered her doing the same thing. She did appear particularly pleased but recovered sufficiently to reveal that among the 100 guests coming to dinner 2 1/2 hours later would be her 9-year-old daughter, Amy.

A fact sheet prepared by Mrs. Carter's staff and distributed to reporters indicated that dancing had been trimmed from the after-dinner activities. "I just kind of know what Jimmy likes," Mrs. Carter said of the deletion, indicating that she fully expects her husband to go upstairs and work, once guests had gone home. That was what they had done when he was governor of Georgia, she said.

However, Gretchen Poston, White House social secretary, said the dancing was dispensed because, "Mrs. Carter and I thought a nice dinner and marvelous entertainment would be enough. Dancing doesn't necessarily have to follow."

Among the 100 dinner guests were to be Vice President Walter Mondale and Mrs. Mondale, Secretary of State Cyrus Vance and Mrs. Vance, Treasury Secretary W. Micheal Blumenthal and Mrs. Blumentahal, U.N. Ambassador Andrew J. Young and Mrs. Young, several members of Congress, a trio of governors, including Dolph Briscoe of Texas, several campaign workers and members of the Carter family including son Jeff, daughters-in-law Caron and Annette, and the President's sister, Ruth Carter Stapleton.