* Awful: This is a common adjective meaning extremely unpleasant or bad.
* Blob: This is a noun that refers to a shapeless mass or a large drop of liquid.
While "awful blob" might sound like it could be slang, it's simply a descriptive phrase. You could use it to describe something unappealing, messy, or generally unpleasant.
It doesn't have a specific origin in any particular time period and isn't considered slang.