The first time I installed Eclipse on my MacBook, I found the default font size too small, especially fonts in the package browser -- they were smaller than what I had on my linux or Windows Eclipse installs. They were so small, I could not read them on my 13.3 inch screen.
Searching the web, I found many users have the same problem. Yesterday, when I was editing my eclipse.ini file, I found the problematic option that makes the fonts too small:
So, if you have the same problem, you can edit $ECLIPSE_HOME » Eclipse.app » Contents » MacOS » eclipse.ini and remove the mentioned line of the options.
Mac OS X Hints