how to continuously display a file of its last several lines of contents

I am trying to find a Unix command (combination, maybe) on how to continuously display a file of its last several lines of contents. But during this displaying, I want some of the top lines are always displayed on the screen top when the rolling contents reach the screen top.

Is that possible?

1. Suppose I have file, "job.sta", the first 2 lines are:

   job name, John's job on 2013-Jan-30,...
   Tab1, Tab2, Tab3
   0, 1, 2,
   1, 90, 89
   2, 89, 23
   ...
   

2. This file is on its running, its contents are growing, and I don't know what line it's going to end.
3. So I want to display (always) the first 2 lines when using tail command, when the updating contents reaches a Unix shell screen top. I am using PuTTY at the moment.

Reference: http://www.unix.com/unix-dummies-questions-answers/172000-head-tail-how-display-middle-lines.html