Use grid padding to increase the size of the space of gap between each column and row. Depending on your data set and design preferences, increasing the padding size can make for easier reading and comprehension, especially if used with other formatting options like alternate rows.
Click the Grid Padding button 
from the Component ribbon to add padding to all columns and rows in the grid (red arrow below):
Grid padding can also be enabled and disabled from the Matrix Grid view of the Formatting Panel (red highlight below):
Example
Here we see a matrix grid with no padding added:
Here, we see the same grid with padding enabled; the space between the columns and rows is increased, making it easier to pinpoint each data cell.
