It should probably be Dictionary of Medical Namesakes unless it is more about the men than the diseases which take their names. Using an unfamiliar world like eponym lends itself, however, to the obfuscating nature of science.
For example, Oxford gives these two definitions for eponymous: “(person) giving their name to something” and "(thing) named after a particular person." I argue here that the former is correct, and the latter is not. Merriam-Webster’s gets it right, but does so in a rather confusing manner: "Of, relating to, or being the person or thing for whom or which something is named." Huh? The American Heritage Dictionary of the English Language doesn’t even include what I would deem proper usage: "named after something else or deriving from an existing name or word."
When researching this piece, I learned of a couple of twists. More straightforward are the common noun namesakes with eponymous inventors. For example, Captain Charles C. Boycott was the eponymous land agent firstly shunned by the Irish Land League; James Brudenell, the seventh earl of Cardigan, is the eponymous wearer of the buttoned-down sweater; and the 4th earl of Sandwich, John Montagu, is the eponymous man who popularized the sandwich.
Others include chauvinism, gerrymandering, jumbo, leotard, luddite, lynch, masochism, pompadour, sadism, and sideburns. I find these interesting because their origins have been lost to history, to the point that we do not even recognize their proper-noun origins by capitalizing the first letter.
Just to add something I found a little perplexing: Xerox, which was originally the Haloid Company before renaming itself after its big, new product, is a namesake for the eponymous photocopiers, Xerox machines, which are now eponymous nouns and verbs for photocopiers and photocopying, respectively.