An object in this meaning is the same thing as an objective[?] or task[?]. It comes from old project terminology and refers to the act of actually performing something according to a plan, or rather "according to a project" (the word "project" used to mean "plan").
... there are 14,078 people, 4,578 households, and 3,731 families residing in the town. The population density is 1,322.5/km² (3,428.5/mi²). There are 4,661 ...