This has been discussed before, but let's start from clean plate. I ask you to first mention game title, then your experiences with it on the tablet. Also some details about your tablet please.
Asus Transformer Book T100TAM
Atom 1,46 GHZ
Attachable/detachable keyboard with touchpad
I have played this only a bit, but it works well enough. First touch on a screen moves mouse cursor onto location, second touch is a 'click'. So we can see expected result of an attack before attacking.
Game works well most of the time. Minimap works well for scrolling the map around. But care must be taken when plotting movement path: it is frustratingly easy to make missteps. Hot seat works within game's limits: 2 instances of the game (start the game twice) are required to run for 2-player game. Then it is just handing the tablet over across the table to next player. Much of the typing, if necessary, can be done with with Windows' virtual (touchscreen) keyboard, and its backspace key can be used to reduce movement path. I would love to have Esc key on it for complete clearance though. I can recommend this game (on touchscreen tablet) for small scale (up to 4v4 units) scenarios.
Battle for Wesnoth
On last Christmas I used tablet to show this game to my little sister. Touchscreen works mostly fine for the game, and I don't recall having any significant problems with it. Can't have right-click menu though, but game's UI has menu button with equivalent commands behind of it. I can highly recommended this game for touchscreen tablet.
You know what they say, don't you? About how us MechWarriors are the modern knights, how warfare has become civilized now that we have to abide by conventions and rules of war. Don't believe it. MekWars