I visited the Purdue OWL, where they provide much MLA Works Cited guidance. I did not find any guidance specific to PowerPoint presentations, but I did find this:

The example file you point to has no author information available on the slides. In PowerPoint, you can use File > Properties to check for author information, but that information might only provide a clue, and should by no means be considered reliable (it's more likely to contain information related to the owner of the computer that the file was last saved on, rather than information about the originator of the intellectual content. For example, in the file you reference, the Author is listed as "jru" and the file was last saved by G. Pringle. The file's Properties information also reveals that the file was created in 2008 and last saved in 2010.).
MLA no longer requires a web address, but, a URL is not prohibited, either. With so little information available for this citation, you might want to provide one anyway:
"The Charge of the Light Brigade." 2010. Web. Microsoft PowerPoint file.
<http://www.sequim.k12.wa.us/151920831173212473/lib/151920831173212473/
The_Charge_of_the_Light_Brigade.ppt>
Based on the information available, that's how I'd cite it.