As far as category is concerned, Cat C is standard in EU as generally MLW is set not to exceed 65T.
Regarding flap 30/40, it is not based on 30, but based on slowest possible speed, thus 40 is taken to enable category C.
Table above uses rounded figures at 5t intervals, digital files provide more accurate data and sometimes weights are directly derived from lb tables for certification converted into kg, thus the odd numbers in some operators...
In addition, wing configuration is to be taken into account, winglets, scimitar, or none...