Simple coding problem, Tabula Recta

public class Main {
    public static void main(String[] args) {
        char array[][];
        array=createTable(27,27,"ABCDEFGHIJKLMNOPQRSTUVWXYZ");
        printTable(array,27);
    }
    private static char[][] createTable(int x, int y, String s) {
        char array[][]=new char[x][y];
        int index=0;
        array[0][0]=' '; 
        printTable(array,x);
        for(int i=1;i<x;i++){
            array[0][i]=s.charAt(index);
            index++;
        }
        index=0;
        for(int i=1;i<x;i++){
            array[i][0]=s.charAt(index);
            index++;
        }

        int column=0;
        for(int i=1;i<x;i++){
            for(int j=1; j<x; j++) {
                array[i][j]=s.charAt((j-1+column)%(x-1));
            }
            column++;
        }
        return array;
    }

    private static void printTable(char[][] array,int x) {
        System.out.println();
        for(int i=0;i<x;i++){
            for(int j=0;j<x;j++){
                System.out.print(array[i][j]+" ");
            }
            System.out.println();
        }
    }

} 

First thing ... comments and sensible variable names and code. For instance, why are you passing x,y to createTable when you only ever do anything in terms of x and in any case, everything can be inferred form the sizeof the string ... never mind!

I couldn't really work out what you were trying to do, though obviously you tried to print from the the middle of the string array to the end, and then from the start to somewhere in the middle.

I've not made any attempt to fix that in the snippet above as I prefer the modulo operator. "%". It is the remainder from a division and very useful when trying to wrap around from the end of the array to the front as you iterate.

In the line:

array[j]=s.charAt((j-1+column)%(x-1));

j-1 is iterating from 0->25, i.e. the character indexes of the string. Column is your start position in character string, and the %26 will do all the wrapping for you, so when the start position (column) is somewhere in the middle of the string and j-1+column gets to 26, beyond the last character in the string, 26%26 wraps it back around to the 0-th character, and at 27, 27%26 wraps it to the 1-th char, etc etc.

Sorry if that is not clear, print out all the variables inside the iteration and it becomes obvious :-)

Rob