Electrum calculated the fees for your transaction to make sure it confirm faster. Usually, if the transaction is less than 1000kb and the amount is large, it will go through without fees just fine.
I think it is 1000 bytes not 1000 kilobytes.
TX will get higher priority if it is higher than 0.01
BTC and in your case it may work.
Just key in a lower amount into the gambling site and deposit it.
Yeah, if your transaction isn't for urgent needs, sending without fees or with lower fees is okay but I would stick with 'pay miners' and atleast use 0.00001
BTC/TX_with_<1000, 0.000001
BTC would work too.
-MZ