What's interesting is that in many cases I've noticed (when viewing my webpages on my hard drive using Homesite's browse mode) that the ads I see are different and often much better suited to the content on the page than the ads Google actually serves after I upload the page.
Google sees the file name and the directory name (where the file is residing) when it is on your local pc. Just pick up the html file and experiment by keeping it in different directories, and see how the ads change.
For e.g, if your file is in C:\design\file.html you will see ads related to the keyword "design"
Try changing the folder name and see how the ads get changed. ;)
Looks like one of the factors in the Google AdSense targeting algorithm is the analysis of the URL or path of the page.