Burial Flags

Copyable Spreadsheet

Heading deeper into the temple, you come to a room that appears to contain a crypt. On the floor is space for three side-by-side stacks of banners - and there are twelve banners here, but they’ve scattered about and are somewhat moth-eaten (see below, bottom). On the wall of the crypt, you notice a strange carving (see below, top). With some study you can stack the banners correctly - top to bottom, in three piles of equal height. After doing so, you notice a confusing message - luckily, you’ve brought a pair of scissors.
What were these banners used for?
First: _ _ _ _ _ _ _  _ _ _ _'_  _ _ _ _ _ _
Second: _ _ _  _ _ _ _ _ _
Finally (Answer): _ _ _ _ _  _ _ _ _ _