The data listing window is shown below.
The Data pane lists the data samples collected by the logger. If the data rollover check box in the setup window was cleared, the earliest data samples are listed. If the data rollover check box was checked, the latest data samples are listed.
The column width is adjustable by using the left mouse button and dragging the column to the desired width.
The 
icon next to the data sample indicates an alarm condition. That is, one or both the data channels are outside the minimum and maximum (alarm low and alarm high) thresholds that you set. An L (low alarm condition) or an H (high alarm condition) is placed next to the sample that is actually outside the threshold.
The amount of data samples shown (and printed) can be reduced by using the data filter.