If you are referring to the rice mats they use in the floor, it's tatami (畳)
Tatami mat
Tatami.
A Japanese sleeping mat is called a futon. A futon sits upon a woven mat called a tatami. These types of beds have been used for thousands of years of Japanese history.
Japanese straw mats are called 畳 (tatami) in Japanese. The pronunciation is somewhat like "tah-tah-me".
Floor mats in traditional Japanese homes are called Tatami Mats.
tatami
In japan, mat is Tatami and we just call it Judo Tatami.
Futon (small pullout bed), or a Mat.
Matt is written in Japanese as マット (matto). You would pronounce it like 'mat-toe'.
It is referred to as a bamboo sushi mat. They are typically wrapped in plastic for sanitary reasons. They help the sushi chef form a nice round roll for the presentation, but they can use it to make different shapes such as tear drops. You can buy them online at: http://www.homesushibar.com/kitchen-knives-tools/sushi-tools/
a gauze mat
A heat proof mat