Previewing record fields
When you enable previewing a record field, its values are shown in a separate preview row below the row(s) displaying other record fields. This feature is especially useful for viewing the contents of large text fields.
You can limit the number of text lines in the preview row by specifying their number in the Preview lines count field on the Options tab of the Customize View window (you can access the Customize View window by selecting View > Customize View).
To enable previewing a field:
Right-click its column heading and choose View > Column > Preview This Column from the pop-up menu.
To disable preview:
Right-click any column heading and choose View > Column > Hide Preview from the pop-up menu.