He earned a Bachelor degree from the University of Hawaii in 1937, and also studied at the California School of Fine Art, at Columbia University with Meyer Schapiro and at the New School of Social Research in New York City.
From 1946 to the 1970s, he taught at the Brooklyn Museum Art School where his students included Frances Kornbluth. He also spent many summers painting on Monhegan Island in Maine. Upon retirement in the 1970s, Tam returned to Kaua"i and died there on January 3, 1991 of lymphoma.
Tam is best known for his semi-abstract landscapes showing both land and sea, such as From Cliffs to Evening.
The Addison Gallery of American Art (Andover, Massachusetts), the Brooklyn Museum of Art (Brooklyn, New York ), the Butler Institute of American Art (Youngstown, Ohio), the Corcoran Gallery (Washington Doctorate C), Des Moines Art Center (Des Moines, Iowa), Farnsworth Art Museum (Rockland, Maine), Fisher Gallery (University of Southern California, Los Angeles), the Hawaii State Art Museum, the Henry Art Gallery (University of Washington, Seattle, Washington), the Hirshhorn Museum and Sculpture Garden (Washington, Doctorate C), the Honolulu Museum of Art, the Lowe Art Museum (University of Miami, Florida), the Metropolitan Museum of Art, the Museum of Modern Art (New York City), the Mildred Lane Kemper Art Museum (Washington University, Street Louis, Missouri), the Newark Museum (Newark, New Jersey), Reading Public Museum (Reading, Pennsylvania), the San Diego Museum of Art (San Diego, California), Sheldon Memorial Art Gallery (Lincoln, Nebraska), the Smithsonian American Art Museum (Washington, Doctorate C), the University of Michigan Museum of Art (Ann Arbor, Michigan) and the Whitney Museum of American Art (New York City) are among the public collections holding works by Reuben Tam.
Married Geraldine King, May 20, 1948.