Mandolins can usually slice paper thin, especially the higher quality mandolins. When it comes to meat, it is a little trickier. They do pretty decent on harder meats (like salami or pepperoni), but softer stuff like deli meats it will probably struggle to slice, and to slice consistently.

https://www.reddit.com/r/AskCulinary/comments/137qy5w/mandolin_question/