For an e-commerce site where a given product may be sold in different packages, you can either have each product package stored as a separate product, or use a second table to store the different formats of the product, where the rest of the generic product info is taken from a main product table.
For example, you'd have a product table, that contains information that applies to the product regardless of which format is being considered:
ID | name | brand
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1 | Product 1 | ACME Corp
2 | product 2 | ACME Corp
And then you'd have a product_format table, which contains the different packaging variations that product might have. If a product isn't sold in any different formats, then you could just have a single row here that contains the price, without specifying the format, since you won't need to show that information.
ID | product_ID | format | price
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1 | 1 | 200g | 19.99
2 | 1 | 400g | 37.99
3 | 2 | null | 8.99