If you have a TAX associated with a product and add it, the sub total is the base plus tax.  So on the line item you have the tax. The you add multiple ones with the TAX and all total up.

However, you can't remove the TAX field underneath the subtotal, you have to add the tax manually rather than selecting a pre-made tax rate in that field and when you print the quote it shows the total price but not the tax calculation if you use the product tax rate and I can't seem to get all these individual product taxes to total and show on a quote.

All-in-all fairly useless if you have multiple tax rates for products etc. And even if you didn't.