This is a copper inkstone, or ink box, which is used to grind ink when writing a brush. It says, "Don't take it, use it in time, be comfortable and enjoy it for a year." Those blue-green things in the box are oxides produced by copper oxidation. They look like antiques, and their value can only be determined by appraisal. You can Baidu, the picture of copper inkstone seems to be similar to yours. Bless the landlord to get rich.