Paid plans only The Inspect tab only allows you to view one object at a time, and often also includes a great deal of information, much of which you may not be interested in. Clicking the eye icon (circled in red below) beside values in the Inspect tab adds that single value to the Watch tab. This allows you to combine different values from different objects in to a single space, as well as reduce the displayed values to just the ones you're interested in.
In the Watch tab, values can be edited as with the Inspect tab.
The Watch tab shows crosses instead of eyes to the right of the values. Click the cross to remove the value from the watch. Note if you are watching a value from an object and the object is destroyed, the watch value will automatically be removed.
Category headers also have their own eye or cross icons. Clicking them will add or remove the entire section to or from the watch.