Please open your Excel file, select your cells and copy them to clipboard.
Click in the "Paste Textbox" below and hit "Ctrl" + "v" from your keyboard.
Once you see your items in the textbox, click on the "Review Items" button.

Please note that items copied from Excel must consist of only two columns (quantity, model) and must be in the correct order, quantity first and then model.
Your pasted information should look like the following example: