The Select columns for data export dialog is used to to determine the data you want to export. The dialog contains all possible columns for the grid and those that are currently displayed in the panel are enabled for export by default.
The dialog is accessed by right-clicking in a grid area of the Explorer panel then selecting Operations »Export Data from the context menu.
Column list - enable/disable the desired data you want to export.
Select All - click to select all the data in the list.
Deselect All - click to deselect all the data in the list.
OK - after clicking this button, the standard Windows Save As dialog will open. Use it to define where and with what name the exported file is to be saved.