If you wish to delete data from this panel, you will need to modify the Experiment in LabAuthor.
Open the Experiment and Paste Alias the LabTutor Data Panel (by right clicking on the Panel and selecting Copy, then right-clicking in an empty space and selecting Paste Alias) to create a copy of the Panel.
Change the Display Mode of the new Data Panel to Standard (Right-click | Properties | Display Mode):
You can then use the Alias Panel to delete Data (since the Panels are Aliases the Data is linked)
To see this functioning within LabTutor, download this example Experiment (LabTutor 4.5.2 or later is required to open this file).