What makes an island mysterious?

Planning for the Maritime Campaign. It won't start for a while, if ever. But one thing I realize I need are less historical pastiche nations/islands, and more weird crazy shit. So to help me along during game times, when I'm sure the players are bound to decide to explore islands I haven't filled out or decided to be the home of a module, I've got this random table cooked up.

Of course, this is only a first draft.

Mysterious Island Random contents:
Roll 2d6

2 Important Clue
3 Powerful Monster Lair
4 Witch
5 Ruins/Dungeon
6 Common Monster Lair
7 Settled
8 Empty
9 Hermit
10 Cursed
11 Unusual Environment
12 Roll 2 times

Important Clue: Someone or something here will point the PCs toward the goal of their quest.

Powerful Monster Lair: Dragon, Giant, Cyclops, Bronze Golem, Vampire, etc.

Witch: Random alignment, may Charm, Polymorph, attack, scare off, seduce, imprison, etc. the PCs.

Ruins/Dungeon: Lost City, Caverns, Temple, Stronghold, etc. Could be inhabited, or empty.

Common Monster Lair: Normal animals, humanoids, or low hit die creatures.

Settled: Town/City, Stronghold, Colony, Camp

Empty: Nothing to see here, but foraging and water available.

Hermit: Crazy, Sage, Spell-caster, religious, guardian

Cursed: The island, its inhabitants, certain locations, or visitors are cursed.

Unusual Environment: Unnatural physical features, flora or fauna.