Hide table and its impact on visualisation

Hello,

I've found that in one raport, I've got a custom calendar and while I hide the table with this calendar, the visualisations breaks (they disappear). In another reports, I also got custom calendars (different types) but hiding the table doesn't affect any charts. In all of the raports, these calendar fields goes into an axis. 

Is there a way to distinguish if hiding certain table would/should affect visuals or not?