EDIT: Clearing my post to reduce the mess. Polecrab anwered my question but I haven't noticed. Thanks.
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This is normal, the inputs never exactly match the outputs so it sends slightly more and you get some change back.
I understand a block carries out other transaction and this is normal.
Is it normal also some extra of my coins flow out from my wallet and get there back later?When you send a transaction a random amount is charged. It depends on the quantity of inputs and it's always bigger then the amount you've specified. After the transaction is completed you recieve the overcharged amount back.