Scrollbar of datatable scroll too much

The scrollbar of my table scrolls too much when I press arrow down or up, for example: enter image description here

Is it possible to change the amount of pixel of scrollbar move ?

I use scrollY: 21.1rem for the scrollbar, but I see something strange here:
enter image description here
enter image description here
enter image description here

That’s what I see when my table scroll, is it normal?