Melba Toast

According to The Laws of B'rachos (page 373):

Brocho before eating this: Hamotzi Lechem Min Ha'aretz

Brocho after eating the proper shiur of this: Bentching

According to Halachos of Brochos Handbook (page 60):

(Note: this is provided that the Melba Toast was made from bread specially baked for Melba Toast, as is normally done in a factory. If made at home, follow above.)

Brocho before eating this: Borei Minei Mezonos

Brocho after eating the proper shiur of this: Al Hamichya

If one is Koveah Seduah on this item, Hamotzi Lechem Min Ha'aretz and Bentching are required.