that looks like a typical Fungia species, (the pink edged with bleached white on the right)
these coral often bud and produce little mouths that form new babies
these babies will grow upwards off the central fungia parent, parent often dies but not always
leaving many of these little babies behind.
this is often a response to survival, or breeding, environmental conditions etc
http://www.wetwebmedia.com/fungiidreprofaqs.htm
this link has some pictures
cheers dave