I would agree that it's not easily comprehended... but "unreadable?" Well, not exactly. There are a lot of hints in the plain-text we can see; hints suggesting some sort of print-oriented device or operation.

But your actual question is harder to answer, based on what you've told us

The tool wich which you opened your .pm file with might make a difference -- among other things, in whether this is a typical extract; the entire content of the module; or an intermittent sample, in which the program that opened the file merely threw away characters that weren't in its vocabulary.

So, please tell us: was it a hex editor; a text editor that will (I don't see any examples here) render certain non-ASCII characters as boxes (and perhaps etc) any editor that quits on anything it takes to be EOF; a debugger? And, not just BTW, in what OS did you open it?