For a product with multiple, variant SKUs, there are several scenarios, described below.
Multiple, variant SKUs use the same volume price values
In this case, the volume price table is displayed for all SKUs but it does not change when a SKU variant is selected.
Multiple, variant SKUs use different volume price values
Your catalog may include a product with multiple, variant SKUs that use different volume price values, for example, SKU 1 uses volume price scheme A and SKU 2 uses volume price scheme B. In this case, the volume price table changes depending on the SKU that is currently selected on the Product Layout page.
Some SKUs use volume pricing and some do not
In this case, the volume price table is only displayed when a SKU is selected that uses a volume price.