Bulk adding items and units

I'm working on an e-commerce project. Besides the traditional flow of category pages and single product pages I'm building a view where expert users should be able to add multiple products and at a time to a shopping cart.

I'm sketching on a table that contains the full list of the brand's products (80 products or so). The reason I have chosen a table (for now) is to display all the products since the user will not know the name of every product and therefore need some kind of visual reminder. The user should be able to select the products she/he wants to buy and specify the amount of the selected product.

For example, the user wants to purchase 4 units of Product X and 2 units of Product Y.

What is a good design pattern for adding multiple items and multiple units from a list or table?