If you have only four permissions Add/Edit/Delete/View then you can create table structure as mentioned below :
User Table :
Columns :
UserId (PK),
UserName,
FirstName,
LastName,
Password,
IsAdmin (bool)
Modules Table :
Columns :
ModuleId (PK),
Name,
Description,
Priviledges Table :
Columns :
PriviledgeId (PK),
UserId (FK),
ModuleId (FK),
IsAdd (bool),
IsView (bool),
IsEdit (bool),
IsDelete (bool)
Note : Above structure is only for the basic functionality. It can be enhanced more as per the requirement