This has been unanswered for some time. Maybe this is still helpful.
The main problem here is cell arrays of (repeated) text and numeric. Don't use those unless you have to, and you probably don't.
>> T = table(categorical({'A','B','C','B','B'}'), ...
[1,2,3,4,5]', ...
categorical({'Car','Van','Car','Car','Car'}'));
>> cats1 = categories(T.Var1);
>> [~,order1] = sort(countcats(T.Var1),'descend');
>> T.Var1 = reordercats(T.Var1,cats1(order1));
>> cats3 = categories(T.Var3);
>> [~,order3] = sort(countcats(T.Var3),'descend');
>> T.Var3 = reordercats(T.Var3,cats3(order3));
>> sortrows(T,["Var1" "Var3"])
ans =
5×3 table
Var1 Var2 Var3
____ ____ ____
B 4 Car
B 5 Car
B 2 Van
A 1 Car
C 3 Car
