Always display the first few lines of a buffer in Vim

You could open the file in two windows (command line: vim -o file file, or ctrl+w n :o file) and then one is fixed and you can scroll in the other window.

If you want to see the first 5 rows press ctrl+w 5 _.

If you're working with datatables alot, you might want to take a look at the csv plugin. it has the :HeaderToggle command that does exactly what you want, and many more commands that you might find useful.

In this case it is convenient to use the preview window (see :help preview-window). To open the preview window showing the first, say, eight lines of the current file, issue the following commands.

:set previewheight=8
:pedit +1

Use the :pclose command (:pc, for short) or the Ctrl+W, Z shortcut to close the preview window.