How to correctly set the dimensions of the camera?

Question

Unity

I'm trying to build a grid on the stage (andriod), it turns out that

How to build a grid so that the camera is in the center of the grid, while moving the camera does not go beyond the grid?
My script is like this

public class Cells : MonoBehaviour{
    public GameObject Cell;
    const float SizeW  = 1f;
    const float SizeH  = 1f;
    public int WidthTable  = 10;
    public int HeightTable = 10;
    void Start(){
        for (int y = 0; y < HeightTable; y++){
            for (int x = 0; x < WidthTable; x++){
                Vector2 pos = new Vector2 (y * SizeW, x * SizeH);
                GameObject cell = Instantiate (Cell, pos, Quaternion.identity) as GameObject;
                }
            }
        }
    }