Yes, you have probably guessed correctly. What you see here are all five of George RR Martin’s A Song of Ice and Fire books stacked on top of each other, and the stick note tabs indicate a death on whatever page they’re attached to. Sometimes more than one.
As you can see, the book’s bloody reputation is not without merit. Yes, only maybe a dozen or so of these are “main” character deaths, the kind that shock and awe the HBO audience on Sunday nights, but the series has a higher bodycount more than pretty much any other series, outside of ones where entire planets get nuked.