Pineal cyst of 0.7x1.0 x1.0 cm abut to tectal plate does this mean its causing damage? what does it mean to be multilocular?

Pineal cyst: It sounds like you're reading from a radiological report, which describes the cyst's locale (abutting the tectal plate, a part of the skull). "abut" means to be next to, or to have a common boundary with. It does not mean damage. "multilocular" means the cyst has multiple pouches rather than only one. Please discuss these findings with your own doctor so that s/he can address your concerns.

Depends: Abut means that the pineal cyst is adjacent ; touching the tectum. Pineal cysts are common ; usually asymptomatic. If large enough to exert mass effect on tectal plate it may cause parinaud syndrome and even cerebral aqueduct compression(rare). Larger cysts or those with atypical features (multilocular) need to be followed to ensure they do not represent cystic pineal neoplasms (e.g. Pineocytoma).