I think of it more ( When it comes to cargo and food stuff) as pallets of the stuff like we have today in modern grocery stores. were basically there is a bottom pallet (wood/metal/plastic) and then its stacked god awfully high wrapped in Shrink Wrap and fancy giant Zip tie things and then bam shipped off and out to its destination.
On the Slave note: They should ( if we need it to be increased at all) take up 2 cargo space because they are still slaves and would not have the same comforts as say a passenger.
