One of the features setting goal values will unlock for you is conditional formatting in tables.
After you have set a goal for a metric, toggle on "Show Goals" from any chart you're viewing as Type: Table, and you will see values change color depending on your respective goal values. Let's go deeper:
If you have 1 goal value set (just the good value), the Green/Red will display corresponding to your preferred movement arrows.
If you have no goal values set, only your variance values will display with conditional formatting (when "Show Goals" is toggled on).
Troubleshooting goals: a major point to remember is that goals correspond the display increments. If you aren't seeing conditional formatting appear, chances are you are viewing a different display increment than what was set for that metric.