I saw this anvil today in somebodys yard, trying to get hold of it. What is the buldge on the side? Any info on it perhaps?

That type of anvil is known as a Coachmaker's anvil.  They were made by Peter Wright, Foster, and other English anvilmakers.  The two I have are Fosters, dated around 1850.

 

The small side table was used to do so small task.  I am not sure if it was ever established exactly what that was.  They are not common, but there are a lot of them out there.  If I remember correctly, there was a large (600 lb +) one on display at the ABANA conference in Flagstaff in 2000.

Spring, coach and carraige makers used that shelf to form small hardware that needed more than a 90 degree bend. Common factory feature available in the late 1800's to eary 1900's, non-standard anvils were usually sold to specialty shops in populated areas where trades diversified.  

Some modern european style anvils have a similar side shelf at face level to aid in detail work. At least one smith I know has welded one on to his anvil after taking classes and finding out just how useful they are.

You may note that the shelves are on opposite sides. In both cases, the shelf is on the far side of the anvil from the smith, the difference is the way English and German smiths point the horn while working.

A William foster just went through on eBay that looked identical to that anvil, it had a very small step on it as well.

I was told the side clip was used for forging clips used in coach work.  The side shelf is not in line with the face like on German anvils similar design different purpose.