Europe dwarfs Thailand: about 10,180,000 km² km² against 515,720 km² km². At true size Europe is about 19.7× larger — the whole of Thailand fits into Europe roughly 19 times.
The old Mercator map treated both about equally (1× vs 1.1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Thailand fits 19× into Europe.