Is it possible to declare global array of type String[][]?

To create array normally you need to at least set first dimension of array, but normally you do it like

1) new Type[dim1][dim2]..[dimN]

You can skip dimensions if you initialize arrays with elements like

2) new Type[][]..[]{{..{elements},},..}}

But if you are initializing your array with elements in the same place where you are declaring it then you can skip new Type[][]...[] part and just use {{..{elements},},..}} like

3) Type[][]..[] myArray = {{..{elements},},..}}

In your case you are having case 2) because you are not initializing your array in place you declared it. So instead of

p[][] = {
  {"  ","A","B","C","D","E","F","G","H"},
  ...
  };

you need to write it as

p = new String[][]{
  {"  ","A","B","C","D","E","F","G","H"},
  ...
  };

Try this type of initialization:

public static String[][] s = new String[][]{
    {"A", "B", "C"},
    {"D", "E", "F"}
};

This would define dinamically your multidimensional Array

You can only use array constants in initializers.

Therefore:

// will compile
public static String[][] p = {{"foo", "bar"}};

// will compile
public static String[][] p;
static {
    p = new String[][]{{"foo", "bar"}};
}

// won't compile
public static String[][] p;
static {
    p = {{"foo", "bar"}};
}

Understand that p is a variable of type String[][] , thus initialize it in the following way

p = new String[][]{...}; 

In the above code p which is of type String[][] is assigned to an object initialized of the same type.

when you try to assign values, you can specify the indices like this

p[i][j] = "value";