In form, a writing table is a Pedestal desk without the pedestals, having legs instead to hold it up. This is why such tables are sometimes called leg desks.
The writing table is often called a "Bureau plat" when it is done in a French style such as Louis XVI, Art Nouveau, etc. When a writing table is supported by two legs instead of four, it is usually called a Trestle desk.
The writing table is also sometimes called a library table, because it was often placed in a rich individual's library. This was the room in a house where a gentleman would keep literature and also do his business transactions. The library often housed, in addition, a round desk called a Rent table and sometimes a Drawing table. The term library table is sometimes applied indiscriminately to a wide variety of desk forms, in addition to being used for writing tables. Let the scholar or the buyer be wary.
Some writing tables have additional drawers built above the surface. In this case they are often called Bureau a gradin instead of writing table, unless they have a more specific form, such as that of a Carlton house desk.
As with many other desk forms antique writing tables were sometimes built with what was, at the time, a complex mechanism of gears and levers to make sections slide out or pop up when certain panels were pulled. In this case one sometimes called them a Mechanical desk.