Thanks for taking so much time with the answer, CraigR.
I am using PowerStore for a clothing line. Yes, I didn't show all the sizes such as Unisex in my question.
I will read over all that you've shared and hopefully I'll understand enough to create the size charts as in my posted image.
I may not have been clear though. I don't need to show all the shirts in a size. I just need to show what the measurements are on a size, i.e., Mens Length XXL has an inseam of 37", etc.
"So, to retrieve all of the available sizes for item 1, the mens shirt"
The image I posted is what I am trying to create so client can change values themselves as they need to. The cart itself can show the sizes for the product. This chart is separate from the cart as a reference point so folks know what size is best for them based on measurements.