THE 41st Street Theatre's summer comedy festival, which has been less than uproarious, presented its fifth and final installment last night, a revival of "The Tender Trap" by Max Shulman and Robert Paul Smith. The evening was less than uproarious. "The Tender Trap," for those who missed the original 1954 Broadway version starring Robert Preston, Ronny 'Graham and Kim Hunter, and the subsequent .movie with Frank Sinatra, David Wayne and Debbie Reynolds, is about a New York bachelor. - He does not appear to be an ordinary bachelor. From the moment he sets foot in town, charming, talented and beautiful women find him irresistible. Why? It is never clearly established. The plot also centers on the bachelor's best friend - a married man from Indianapolis who thinks he has developed &Till that cures the common cold and has a wife addicted to wall-to-wall carpeting and talking about braces for their youngsters' teeth. Still another feature is a 22-year-old shapely brunette who is interested in the bachelor, matrimony and a split level house in Scarsdale. - There are moments when the evening is quite funny. Hut the script seems contrived from time to time. Although the cast is earnest, the acting is not inspired. Jean Shepherd is a pleasant bachelor but is not entirely convincing. One of the girls has a Southern accent that is quite fraudulent. However, Kenneth Brooks as the married man, Ellen Evans as the brunette and Lisa Carroll as an attractive violinist give good performances. On a small budget, Jerome Liotta, as he has done throughout the summer, shows imagination with the settings. Mr. Shulman and Mr. Smith let the curtain come down after the married man says to the bachelor and the brunette: "Why don't you two get married?" So they get married and live happily ever after - in a split-level house in Scarsdale, The Cast THE TENDER TRAP, a revival of the Max Shulman-Robert Paul Smith comedy. Staged by Matt Cimber; presented by Barbara Griner and Eleanor Horn; scenery by Jerome Liotla; production stage manager, Tom Glenn. At the 41st Street Theatre, 125 West Forty-first Street. Charlie Reader - Jean Shepherd Poppy Matson - Marcia Levant Joe McCall - Kenneth Brooks Jessica Collins - Rosemary Haley Sylvia Crews - Lisa Carroll Julie Gills - Ellen Evans Earl Lindquist - Merrell Breeden Sol Schwartz - Gustave Sabin