It bills itself as a seafood house, but it’s so much more.  Robert Oliver Seafood has just opened its doors in the old Spike & Charlie’s space across the street from the Symphony Hall. The interiors have undergone a complete overhaul, and the multi-level main dining room is now done up in muted shades of brown, tan and beige. Smart circular banquettes ring the room and sweeps of sheer fabric subtly divide the space. Up front, there’s a small cappuccino and dessert bar, and a large new barroom boasts a dramaticly lighted, bubbling water feature and lots of intimate seating.  The menu offers a list of mezzes and grilled kebobs, New American seafood platters and classic plates such as lamb, roasted chicken and shepherd’s pie. Open seven days for dinner. Free validated parking in the deck across the street.  1225 Cathedral St., 410-528-5950.