Answer:
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
What has roots as nobody sees, is taller than trees. Up, up it goes, and yet never grows?
What kind of table has no legs?
The more holes you cover the lower it goes.
Put into a pit, locked beneath a grate, guarded through the night, yet it still goes out.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?