In Touch Portal you can have different button grid sizes and settings per page.
With the grid settings number pickers you can set the amount of columns and rows. Try changing them from 4x2 to 5x3. All buttons will stay on their location within the grid but the grid expands so the buttons because a bit smaller.
With this option you can set the amount of space between the border of the page/screen and the grid of buttons. If you do not want any space between them, use 0.
With this option you can set the amount of space between the buttons. If you do not want any space between them, use 0.
When you select this option the buttons will expand to use the maximum available space within the grid. This means the background will expand and the icons will take the maximum amount of available space but it will keep aspect ratio.
With this option you can group all the square buttons and position it in the middle of the device. This will create additional margins either vertically or horizontally depending on your grid size and the device aspect ratio.