Time is the start time of the track, as far as we can calculate it. It's actually the last modified time of the file minue the total time offset for Lowrance sonar logs, as we don't get an explicit start time. We do get a time for HB logs and (most) GPX logs.
You'd like to see this data in the track list, or the track properties?
We could add a tooltip to the track-list fairly easily with extra information, although you wouldn't be able to sort on it or see it for multiple tracks at once. Could still be useful though?