Clarified to_dict function description.

data/table.py

@@ -57,7 +57,10 @@ class Table:
         return self._categories_map[category_name]
 
     def to_dict(self) -> dict:
-        """Saves table as a python dictionary."""
+        """
+        Saves table as a python dictionary.
+        Does not include table name. It should be the key of above data structure.
+        """
         data = {}
         data["message_id"] = self.message_id
         data["categories"] = {}