While President Carter entertained the U.S. Olympic team with a White House dinner last night. American swimmers set two world records and added an American record in the would-be Olympic trails. Mary T. Meagher and Craig Beardsley set world standards in the 200-meter butterfly and Tracy Caulkins cracked her own U.S. mark in the 400-meter individual medley.

The finals of the men's butterfly saw the top three finishers better Soviet Sergei Fesenko's gold medal time of 1:56.76. Beardsley set his mark of 1:58.21 in the preliminaries and won the final over 1976 Olympic champion Mike Bruner. Beardsley, of Florida Aquatics, won in 1:58.46, Bruner touched in 1:59.13 and Billy Forrester, Beardsley's teammate, was third in 1:59.40.

All eight finalist bettered the silver medal time of 2:01.2 by Phil Huoble of Great Britain.

Meagher bettered her old mark of 2:07.01 with a 2:06.37 -- more than four seconds faster than the time that won Ines Geissler of East Germany a gold medal in Moscow. Meagher covered the first 100 meters in 1:00.83 and left the field in her wake en route to the record time.

Besty Rapp, 20, of Starlit Aquatic Club, Fairfax, Va., finished sixth in the same even recording a lifetime best of 2:1o.96. Another Rapp, Susan, 14, qualified for the Olympic team Tuesday when she finished third in the 100 meter breaststroke.

Caulkins picked up her second American record winning the 400-meter individual medley in 4:10.61. Caulkins, winner of the 100-meter breaststroke earlier in U.S. record time, would have placed second to East German Petra Schneider in the medley race at the Moscow Olympics, Schneider won the gold medal in world record time of 4:36.29.

Nancy Hogshead, 18, of Florida Aquatic, was second to Caulkins in 4:47.81. Hogshead and Calkins both emerged as national swimming powers at the 1977 national championships in Canton, Ohio.

Caulkins, 17, of the Nashville Auqatic Club, has fallen short in two events of the winning time in Moscow even while setting U.S. marks.

Five Washington area swimmers competed. Jenny Rapp, 17, of Starlit Aquatic Club, Fairfax, Va., finishing 19th in the 400-meter individual medley with 5:00.71. Jude DeSanto of Rockvill, Md., was 39th in the same even in 5:08.22.

Other Starlit entires include Phil Perdue, 21, who was 20th in the 100-meter freestyle in 51.87 and Trent Lyght, 20, 66th in 53.88. Maria Pease was 25th in the 200-meter butterfly in 2:19.