Folksy tales of America's presidents; Presidential Anecdotes, by Paul F. Boller Jr. New York: Penguin Books. 410 pp. $ 6.95.

Most presidents enjoy their jobs, according to historian Paul Boller, who has amassed an impressive collection of anecdotes on all 39 of them through the Carter administration. Some presidents, like LBJ, displayed astonishing vigor. Johnson packed a lot into one day. Between breakfast and bed he once visited five countries in Central America.

The folksy informality that Americans have treasured in presidents contributes to Boller's observations about the rise and fall of presidential reputations - the increasing popularity of TR and Truman, and the declining favor for Jefferson, Wilson, and FDR, who espoused a more dignified statesmanship.