It is well documented that Google Chrome has a multi-process architecture and forks a new Chrome process for a every new TAB or a plugin.
I have got 4 tabs and 1 plugin running:
Here is the process tree: (using Process Monitor)
The visual explain the multi-process hierarchy. During startup there is a browser process which forks a new renderer process everytime a new tab is opened and/or a new plugin process everytime a plugin is opened.
The blog post Multi-process Architecture is an excellent read.
