"Price per option granted" versus "exercising price"?

The Exercise Price is what you have the option to buy the shares for after the expiry date (which may be the same as the vest date, but not necessarily). So you'll have the option to buy shares for 100 Euro at that time. Obviously if the price of shares is less than 100 Euro at expiry, then you wouldn't buy them and the options would be worthless.

My guess on the "price per option granted" is that's the price that you're buying the option for (in other words, they are given to you). It may be important for tax purposes, meaing if you were to sell the options before exercising them, your cost bases for tax purposes would be 0.