Harry looked over at the Slytherin table and saw a horrible ghost sitting there, with blank staring eyes, a gaunt face, and robes stained with silver blood. He was right next to Malfoy who, Harry was pleased to see, didn't look too pleased with the seating ar-rangements.
--Harry Potter and the Sorcerer's Stone
Over seems to mean across in the context. Does it mean Harry looked across/over students at the Slytherin?