Changing padding top 2 columns (with tables inside) on one specific page only.

Hey,
On one my pages I have a section (1 full column) with big title and text. Then below a section of 2 columns with a table in each of them.
The vertical space between the first section (1 col) and the second (2 col) is too large.
I thought about changing and adapting the margin-top (see below) in quick css (10 or 20 instead of 50), but if I do that this is going to affect all other columns paddings in other pages, right ? Is there something I can add to make that change working for a specific page only ?
Hope I’m understandable… Sorry I can’t send you a link (local work…).
Thanks a lot !
Marie

body .column-top-margin {
margin-top: 50px;
}