Name is correct like this. Prior to 2002 the band had just two members and released as ROUND TABLE. From 2002 on all their releases are with Nino as the vocalist. They've put out 1 album and 4 singles as "ROUND TABLE featuring Nino" in the past three years and neither ROUND TABLE nor Nino has put out any solo releases in that time. Basically it appears they added a vocalist with too much ego to just be part of the band so they had to attach her name to the group name.
Discography for ROUND TABLE: http://www.round-table.jp/disc/index.html
Discography for ROUND TABLE featuring Nino: http://www.jvcmusic.co.jp/-/Discographylist/A016988.html
ROUND TABLE on MB: http://www.musicbrainz.org/artist/eac9f2e2-a698-4b04-a471-d6498a24a766.html