Under Administer - CiviReport - Create Report From Template there is one called "Database Log Report". That shows you more or less what's in civicrm_log.
For advanced logging (at Administer - System Settings - Misc - Logging), which I don't think is what you're talking about but just in case, the lack of an activity report is a known issue. The ...
There is an extension which will record exports using civicrm export from contact search. Unless you have this extension installed there really isn't a way to see if there were specific exports of information.
More information on the extension can be found here