below/beneath

English as a Second Language English Vocabulary, Grammar and Idioms
1

[color=red]1-She pushed my head below the table so they would not see me through the window.
[color=darkblue]2-She pushed my head below the table top so they would not see me through the window.

[color=darkred]3-She pushed my head below the table so they would not see me through the window.
[color=blue]4-She pushed my head below the table top so they would not see me through the window.

In which case:
a. My head is under the table top
and in which case:
b. My head might be beside the table but at a lower lever than the table top.

Gratefully.
Navi.

2

She pushed my head under the table (head under the table top)
She pushed my head down below the table top. / down below the level of the table. /down behind the table (beside the table, at a lower level0
I would not use the phrases in your sentences.

3
  1. She pushed my head under the table so nobody could see me through the window.
  2. She pushed my head down below the table top so nobody could see me through the window.
    Are they correct. Please comment.
    Thanks
4

Yes.
All you appear to have done is added the extra phrase to my main phrases, so naturally they are correct.