Increase the gap between variable tab and table boarder under section on form

[shashi123]

Hi Community,

I have issue like, I want the gap between variable tab under catalog variable section on change task form. As shown in below image 

1. red arrows shows the defect image 

2. green arrow shows the expected result 

1.

2.

if any have the solution, please guide me 

Thanks In Advance,

Shashikant Patil.