Allow subtitles for tables and columns

[Philippe-Andre_Lorin]

I would like to add details about some tables and some columns. The right place for these details would not be adjacent text, but text displayed right after the title, in a smaller font. Example :

[Table title] Videogame Systems
[Table subtitle] Regional variants share a single entry (e.g. Super NES = Super Famicom). Combinations of systems have their own entry (e.g. Gamecube + GBA ≠ Gamecube).

[Pch]

I must say that sometimes I wish I could add some info describing a table or field too .
It could be a little pop-up bubble that appears when hovering the field .