Hi Bob, and welcome!
I'll take your pictures in order and give some first impressions.
1 This looks like
Hipparchia sp. There are many
Hipparchia in Greece and they are all quite variable, so I'll compare against the maps when I get home to see what flies in Evia (I'm at work at the moment!!). A possibility is that this is an extremely (anomolously) dark rock grayling,
Hipparchia alcyone - but more on that later.
2 Southern white admiral,
Liminits reducta.
3-7 Common blue,
Polyommatus icarus.
8-9 Meadow brown,
Maniola jurtina.
10 Lulworth skipper,
Thymelicus acteon.
11 I think this is another meadow brown - I'll check for other possibilities when I get home.
12 Wall,
Lasiommata megera.
13-16 Small/Essex skipper,
Thymelicus sylvestris/lineola. On these views I'm pushed to say which - so maybe more later, after others have voiced their opinions!
17 Painted lady,
Vanessa cardui.
18 Eastern dappled white,
Euchloe ausonia.
19 Swallowtail,
Papilio machaon.
20 It's a species of yellow underwing moth. Without a book here, I wouldn't like to say which - I don't know my moths so well...
I suppose I ought to do some teaching now.
Guy