You can copy a column of data from a file without copying other data that is selected. For example, suppose you have a tab delimited file that lists date, time, file size, and filename. You can copy just the column that list the times without affecting any of the other data.
You highlight the following selection, then choose Block > Rect Copy.
When you paste the contents of the clipboard, the following text is inserted in your file:
09:21a
09:22a
09:23a
09:36a
09:23a
09:33a