control classes in csharp

Question

ASSALAM-O-ALAIKUM TO EVERYONE;

can you tell me about how we can indentify  and make control class in c#? in the below, i mention my db's tables:

1>patient info.
2>doctor
3> patient visit
4> patient visit treatment
5> treatment
6> medicine
7>medicine type
8> patient visit medicine
9>visit bill
10>surgery
11>surgery types
12>patient surgery
13>glasses 
14>stock of frames
15>other bills
16>medicine stock
17>unit of measurement
18> register empolyee

note:
i am making "eye information management system"..

regards
sumaira manzoor