Yes - you sure can.
In the repeated section element, when there is ore than one open item line a space is automatically added. The default space between two repeated item lines is 30px, but you can change it.
Following are steps:
1- Create a new blank form
2- Drag a section element
3- Resize it and make it repeated
4- Drag a textbox into the section
5- Just so you see the spaces more clearly - Make the Section have 3 visible , populated items.
Select the Section on canvas and Go to : Properties panel > Element tab > Settings option > Basic category >
- Enter 3 in the 'Num of visible items' property.
- Turn on the 'Populate items' checkbox.
6- Save the form.
7- Publish the form as URL
The default space as you can see is 30px
8- Go back to the form builder and change the space to 10px.