"Pack sizes" refers to the different quantities or amounts in which a product is offered or sold. It simply indicates the various sizes or options available for purchasing a particular item. Full definition
The change in household composition has prompted the growth of small pack sizes for consumer goods which are considered to be ideal for smaller households. (globaldata.com)
Are you like me and always go for the family pack size of ribs for two adults, a toddler and a baby? (mamabearscookbook.com)