Things that are chock-full are crowded or packed. If your neighborhood roller skating rink is chock-full of kids, there's not much room for more skaters.
If your freezer is chock-full of ice cream sandwiches, there's no extra space for your ice cube trays, and if your house is chock-full of sweaty football players, you might want to open a window to air the place out. The adjective chock-full sounds modern, but it's been around since about 1400, originally as chokkeful, which may be rooted in choke, or "cheek."