Once you have selected the data that you would like to download, look for the "Data Files" link in the table at the top of the page
For example, as in this image. If you are in the Data Viewer, as in this image, then you will not see this link. You must go to the table under the image you have created in the viewer and click on either the "Entire Dataset" or "data in view" buttons, depending on how much data you want to download. This will bring you to a screen where you can select the "Data Files" link.
Select "Data Files" and it will take you to a page that lists many options for file formats in which you can download the data, including netCDF, binary direct access, etc. If you want to be able to put the data in a spreadsheet, then you should chose from one of the ascii formats near the bottom of the page.