It appears that you are not pulling information into one field but into one record of a table.
You would have a table with the following fields :
This would be a lineitem in your lineitem table. Take a look at the relationship graph in the invoice starter solution.
Thank you for your help. I think I now have an idea of where to start with this.
Many inventory systems issue a different ID for each size and thus use separate product records for each. This can make for more flexible tracking of ongoing inventory change patterns but also requires more complex layout designs.