Not an expert in journal/dump files. I think dmp files are more relevant for Autodesk personnel (programmers). In there I expect information were they can trace at what position something went wrong so that they can relate this to a specific part of code.
In general I am only looking at the journal files when something goes wrong. Revit keeps track of everything it does and record it in journal files. If something goes wrong I look at the journal files and look for the term 'error' (often found at the end). Depending on what it says you can conclude the possible cause, do a search for a possible cause or upload it to a forum and see if somebody else know what the cause might be. The journal with the highest number is always the latest one and usually of the most interest
Louis
Please mention Revit version, especially when uploading Revit files.
