i wanted to know whether i can create a stand alone cnc machine that has preset csv files in a sd card which will be used with sd card shield of arduino and 2 stepper motors.? also instead of steppers if i use 2 i2c servos will it be possible too?
As you have given no information on your ability in hardware and software, I would doubt it.
You can do this with a raspberry pi connected to the arduino.
The arduino only receives the GRBL co-ordinate information and translates that into data for the stepper drivers. It does not send the GCode or control the machine.
You would need to run Zapmaker's G-Code tools on the Pi in order to send the data to the arduino.
Only 2 stepper motors? Laser cutter?
Have you looked at the ready-made GRBL
Yes, the Arduino can read from an SD card and control two stepper motors based on data in a CSV file. I don't know what you mean by I2C Servo so I can't answer that part. For simple hobby servos the answer is also yes.