In an "out the box" installation of Form Tools, the Export Manager module and the Report Builder module, you'll only see two download / export options on the reports: HTML and Excel. The export options show up as columns of icons, next to each report - as shown in the screenshot to the right.
However, this is totally customizable. As with the previous page on Creating Reports, the functionality to create new Export Options is managed elsewhere: this time in the Export Manager module.
The Export Manager module is an extremely advanced system for generating custom export types. By default, it includes four types: HTML / Printer Friendly, Excel, CSV and XML - but only the first two are enabled, which is why they are the only ones that show up on the reports. To include those, just edit the Export Group in the Export Manager module and change the visibility to yes.
For a lot more information about the Export Manager and how to customize your export options, take a look at the module's documentation.
Multiple Export Types?
If you start tinkering around with customizing the export options via the Export Manager, there's one idiosyncracy to the Report Builder module that you should know about. It will only ever list a single Export Type from each Export Group. (For more information on the difference and definition of Export Types and Groups, see the Export Manager's documentation). Specifically: it will only show the first Export Type.