Often, it will be hundreds of megabytes and sometimes, gigabytes of data.
Which program creates gigabytes of data for no reason?
There is no software that will create gigabytes of removable data. There are system tools, such as WDC, that will remove megabytes/gigabytes of data from a particular software, only to have the software rebuild that data on launch.
Edit: The only software that will create gigabytes of removable data is Google Chrome (or similar), only if the history/cache isn't cleaned often.