This tab contains the last 1000 lines of the server log.  Its a moving update of what is going on in the log.  You can configure in the preferences how many lines you want kept in this window.  Setting a value too high will use a lot of memory.  There is also the option to have the log always scroll when new data is inserted into it.  If this is not selected you will have to scroll to the bottom to see the most recent entries as they are coming in.