/give @p dispenser 1 0 {BlockEntityTag:{Items:[{id:"tnt",Count:64b,Slot:0b}, {id:"tnt",Count:64b,Slot:1b}, {id:"tnt",Count:64b,Slot:2b},{id:"tnt",Count:64b,Slot:3b}, {id:"tnt",Count:64b,Slot:4b}, {id:"tnt",Count:64b,Slot:5b}, {id:"tnt",Count:64b,Slot:6b}, {id:"tnt",Count:64b,Slot:7b}, {id:"tnt",Count:64b,Slot:8b}]}}