As far as I know this is Satoshi's account => https://blockchain.info/address/12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX

I just found this transaction has added some coin to it. Anyone know the source of this transaction as it is sending coins to multiple accounts at a time ?

https://blockchain.info/tx/065ef6b1463f552f675622a5d1fd2c08d6324b4402049f68e767a719e2049e8d

Nothing mysterious. Anyone can send bitcoin to any account

But without reason ? Will u plz send me 0.001 BTC every day ?

Why ask me? You should ask that person. He/she/they might be nice enough to send you some tips.