You can either drag and drop the corners of the table or you edit the position in json: layout > structure. This code should be generated automatically once you created a table in the UI view. But this works only of you have the dashboard in "absolute" mode. If you selected grid it's not possible to freely resize. You can still change this under layout > type: "grid" or "absolute" "position": { "x": 0, "y": 0, "w": 800, "h": 450 }   ... View more

Also impacting table panels created using Dashboard Studio in Splunk Enterprise Version:8.2.6 Build:a6fe1ee8894b ... View more