I wish to show data from multiple tables on one calendar view.
This is highly useful, for example, when you have 2 or more tables that need to be updated separately but are related in function. For example an "Attendance Record" table and a "Vacation Request" table for employees or a team of athletes. For sports teams you could also add in a third "Tournaments" table for scheduled games.
While you could combine into 1 large table, it's likely you will want to have actions or processes use each table independently - for example, different security filters due to the rapid growth of records in an attendance table compared to vacation requests.
...Or performing an quick action on a small table (vacation requests) instead of searching a large combined table.
...Or perhaps you want to see the entire year's games but you only care about the next month's vacation requests.