There is a difference between the two. The cleaners do exactly that, clean and should never be allowed to come in contact with your wine.
Potassium Metabisulfite (k-Meta, camden tablets) are to kill some bacteria and stun the wild yeasts giving your yeast a chance to gain a foothold in your juice (must).
Clean your equipment, rinse then when ready to use spray or rinse with the k-meta. You will be adding k-meta to your wine in certain amounts.
As per your other question. You can split up a packet providing you are adding it to a total of maybe 8 gallons. Once open use the entire packet, do not try to save for later.
These packs are designed for approx. 6 gallon batches but that can be stretched a bit. The yeast will "bud" reproduce but if there is insufficient yeast in your primary you run the risk of external bacteria and foreign yeasts coming in contact and possibly ruining your wine before it has a chance to take off.
Remember to add your nutrients and if using pectic enzymes, they do not do well in a sulfite or fermenting environment. Always allow 12-24 hours between each of them.