I've found a ton of it in Black Fleats Cavern and it weighs an awful lot but isn't really worth anything, so I'm presuming it's quite a useful consumable or material for some kind of crafting, does anybody know what it's for?

I've seen stacks of it around but no use for it as of yet. Perhaps one of those useless decorative items?

i have not played the game so this is speculation on ym part, but, if it is not for show it sounds like it could be used for making armour/clothes

they are for wrapping corpses.

I just took it all, everytime I saw it, just sell it? Profit always wins the day.

Well if I'm being honest, 23 x 3 = 69...

That's alot of weight to carry for about 40ish gold, when I'm stuck in the cave overly cucumbered

If something isn't worth 5x its weight in gold, I generally do not carry it. This game would be awesome if you could use some kind of spell to turn any item into like small nuggets of gold you could later smelt down and craft into coins.
(Yes I've probably played too much RuneScape in my lifetime )