Traditionally, a Mob "associate" (an unmade guy) gets permission to do a job like a robbery, or operate a crap or card game, in return for paying a percentage to the Mob guy giving the permission (as when Jimmy, Henry and Tommy, all unmade, robbed Air France and kicked back $60k to Paulie Cicero in "Goodfellas"). A "made" guy will be given a "living" (like an established Mob bookie joint, whorehouse, loansharking racket) and have to kick back a weekly "nut" to his Capo. Usually that amount is fixed, so he has to pay it whether or not his "living" is earning enough. An example: in "Sopranos," Christopher finally gets "made" and gets a living from Paulie, but he has to give Paulie Walnuts $4k/week win or lose.
As SC said, Paulie Gatto probably had a "legitimate" job (driver? handyman?) at low salary from the Genco Pura Olive Oil Company, which would give him some cover and enable him to declare a small amount of income to keep the IRS off his back. His real money came from the East Side book and the union job that Wayne cited.