there an easy way to set mame for cocktail cabinet for the games that support it?
AFAIK there's no
universal MAME setting, it depends on the game.
First look for a MAME "Game Configuration" menu where you can change Cabinet from "Upright" to "Cocktail". (see Space Invaders, Asteroids on MAME v0.198 or newer)
- These are the games that used a different boardset (Sp Inv) or wiring harness (Ast) for cocktail mode.
Check the MAME "Dip Switches" menu. (see Moon Patrol, Lady Bug)
- Most games with a cocktail mode use a dipswitch setting.
Sometimes there are separate ROMs for the cocktail version. i.e. Carnival (cocktail) instead of Carnival (upright)
If those options fail, check in the game's system menus. (no examples off the top of my head, but it is a possibility

)
The
last easy place to look is the "Video Options" menu.
- The "Cocktail" video option may make some non-cocktail games playable on a cocktail table, but it may not work so well, especially on vector games.
- Avoid this video option if possible.
Worst case, look into making a custom layout (.lay) file for the game.
- I assume you already got the standard art/layout files from Mr. Do's site.
https://mrdo.mameworld.info/mame_artwork_ingame.phpScott