There are at least two bands who share this name(although only one of them has the word "plateau" spelled with the "-eau" IN CAPITAL LETTERS! See below...):
1) PlaTEAU, spelled p-l-a-t-E-A-U, started as a project between cEvin Key (of Skinny Puppy, Download) and Phil Western (sound engineer, producer and songwriter for Download) for when they got arrested for the possession of marijuana and they decided to make a band that was for the legalisation of said drug. The music is thematically similar to Download's but leans to a more psychedelic direction, influenced by house and techno music.

Read more about PlaTEAU on Last.fm.