In theory. If not block colour you could highlight the table in bold and red or something.
However unless you trigger some form of entity state on say first ticket opened your going to need some report expressions to report username on unpaid/open tickets for that entity, and doing that on entity screen with many enties can make things slow to load due to having to run report(s) for each table/entity every time the screen is loaded.
You would probably be better to make two entity screens, the first one filtered to an entity state set on ticket entity updated to set the username to the state.
Then have a seccond normal all tables screen to allow the initial selection.
One issue that may come up though is as you can run multiple tickets on the same entity/table and these could be started by different users is what happens in this event.