South America dwarfs Tanzania: about 17,840,000 km² km² against 945,781 km² km². At true size South America is about 18.9× larger — the whole of Tanzania fits into South America roughly 18 times.
The old Mercator map treated both about equally (1× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Tanzania fits 18× into South America.