Loot Table Wiki Explanations

[Ele]

Some mobs have multiple loot tables each of which has a % chance to be a certain item.

In the instance you posted above.

Table [1] will have 2x items drop from it 100% of the time, any individual item having a 6% chance to be that particular item in that drop slot.
Table [3] will have 2-4 teeth with 100% chance of teeth of being on the corpse.
Undead Dragongut Strings is probably Table [2] with a 20-25% chance of being on the corpse.