The Trip pane shows the track points for a trip. They are displayed on Google Earth as lines to each point and this is the path the aircraft will travel when it is played (see Play Pane).

The trip points are lat, lon, altitude, time at that point and a comment for that point. Click on any row to alter the data in that row. 

When viewing this pane, a cross will be displayed on Google Earth. Clicking on the Insert button will insert the point shown on Google Earth before the highlighted row.

Selecting a row and pushing Delete will delete that row.

At the top of the pane is a number, a date and a Recalc button. This is the fastest way to set the times in the Time field. Just select the date you plan to start that leg of the trip. Then to the left of the date is the speed field (yes, the unnamed field). Set that to your speed in knots. Then click the Recalc button to update the Time fields for that speed. Internally the distances are calculated and the speed is applied and the time at each track point is calculated.