Hi Conner,
Each row will expand to the size of the tallest object in the row. Because of this, you’ll notice that all the stock Method screens either place a grid in its own row or in its own section located at the left side of the screen. Since your grid is the largest object in the row that includes the Competition Models and PowerHandling Models fields, blank space is created below them to accommodate the size of the grid.
Since this data is being displayed in a tab on the Edit Customer screen, your options to remove the white space are:
1) Allow the grid to exist in a row by itself (I recommend this one)
2) Move all the lower fields into the same row as the grid
3) Change the size of the grid to include fewer lines.
I hope this helps.
Audisho