Thomas J. Mosser, the advertising executive killed by a serial bomber last week, was remembered Friday not as a master of Madison Avenue or as a victim of a bizarre criminal but as a caring father who loved touch football and golf, homemade spaghetti sauce and pretty candles.

At a funeral Mass at Notre Dame Church here, Mosser's family and friends spoke of small details of his life that still made them smile. His 13-year-old daughter, Kim, recalled how much he enjoyed gathering his family around the piano to sing Christmas carols."Christmastime was my dad's favorite time of year," she said.

Then, sobbing softly, Kim and two other children of Mosser, Abigail, 21, and Timothy, 16, led the 500 or so congregants in singing the carol he liked best, "O Holy Night."

Mosser, 50, the general manager of Young & Rubicam, one of the world's largest advertising agencies, was killed when he opened a mail bomb in the kitchen of his home in North Caldwell last Saturday. The authorities said the attack was the work of a bomber who has killed one other man and wounded 22 in 14 other attacks since 1978.