How much is too much on a resume?

There is no set parameter to judge how much is too much but any information which adds to your profile and its ‘Brand Value’ is relevant stuff. One should always be on guard against putting in information which is repetitive or has little relevance to the profile.
 
There are certain information with regards to one’s professional career which looses relevance in context to the period for example profile at the start of the career. So one can limit the information to maybe 2/3 lines rather than devoting 10/15 lines in a career span of maybe 15+ years.