'Coin size' refers to the value of the credit, and 'coins' refers to the number of 'coin size' credits being bet on a payline.
Example: Coin size 2 credits, Coins 5.
You are betting 5 times 2 credits on a payline.
There is also a Total Bet option. By multiplying the number of paylines by 'coin size' and 'coins', you get the total bet value. You can adjust this by increasing or decreasing the number of paylines and the 'coin size'.
