Read and Identify Memory Diagram
The "address space" is the number of distinct locations that can be decoded from the two address lines A[0] and A[1]. Two bits can take on 22 = 4 different values.

It's a nonstandard term, but I would assume that "addressability" would refer to the number of addresses that are actually decoded and do something useful. In this case, the three columns correspond to addresses 0, 1 and 2 (left to right), so the addressability would be 3. The AND gates across the top do the address decoding. You could also refer to this as the depth of the memory.

The width of the memory is the number of data bits (D[3] through D[0] down the right sde), which is 4. The data at location 2 (the right-hand column) is 0001.