Lets say you have a few processing plugins on a single track and you want to flip to the second or third processing plugin. Normally you wood open the mixer or channel strip and click on the desired plugin you want to edit.
With the tabs you can directly click the desired plugin you want to edit by clicking on the desired tab.
This tab will shown on the processing plugin that opened in the first place.
A big +1
Take a look at how Studio One does this, if you get the chance - very elegant and clean.
The whole architecture of handling plugins has been well thought out/designed from the outset. The window ‘header’ containing the plugin is always visible and has a view (‘tabs’) of the complete plugin-chain for that track/channel. Clicking on each will bring that plugin to the front ready for editing; its all right there where you are working… very nice.