Simple Tic Tac Toe game
Avoid magic symbols

The character literals 'x', 'o', ' ' appear many times throughout the code.
It would be better to put these in constants, for example:

static final char EMPTY = ' ';
static final char PLAYER_X = 'x';
static final char PLAYER_O = 'o';


Simplify changePlayer

In changePlayer, the newTurn variable is pointless.
The player is either 'o' or 'x', so you can simplify to:

public char changePlayer(char player) {
    return player == 'o' ? 'x' : 'o';
}


Simplify checkIfLegal

The parentheses are unnecessary in the boundary check condition.

And instead of checking if a cell is 'x' or 'o',
it would be simpler to check if it's ' '.

Like this:

public boolean checkIfLegal(int row, int column) {
    if (row &gt; 2 || column &gt; 2 || row &lt; 0 || column &lt; 0) {
        return true;
    } else if (table[row][column] != ' ') {
        return true;
    }

    return false;
}


Not intuitive checkIfLegal

The return value of checkIfLegal is kind of counter-intuitive.
Judging by the name,
my first thought is to return true if legal.
But that's not the case.
A more natural name would be isIllegal.

Formatting

Your code, nicely formatted, would look below.
I simply used my IDE to auto-reformat. You can do this too, next time.

public class Game {

    char[][] table = new char[3][3];

    public void initializeGame() {
        for (int i = 0; i &lt; 3; i++) {
            for (int p = 0; p &lt; 3; p++) {
                table[i][p] = ' ';
            }
        }
    }


    public boolean checkIfLegal(int row, int column) {
        if ((row &gt; 2 || column &gt; 2) || (row &lt; 0 || column &lt; 0)) {
            return true;
        } else if (table[row][column] == 'x' || table[row][column] == 'o') {
            return true;
        }

        return false;
    }


    public void changeBoard(char player, int row, int column) {
        table[row][column] = player;

    }


    public void displayBoard() {

        System.out.println("  0  " + table[0][0] + "|" + table[0][1] + "|" + table[0][2]);
        System.out.println("    --+-+--");
        System.out.println("  1  " + table[1][0] + "|" + table[1][1] + "|" + table[1][2]);
        System.out.println("    --+-+--");
        System.out.println("  2  " + table[2][0] + "|" + table[2][1] + "|" + table[2][2]);
        System.out.println("     0 1 2 ");
    }


    public char changePlayer(char player) {
        char newTurn = 'e';
        if (player == 'o') {
            newTurn = 'x';
        }
        if (player == 'x') {
            newTurn = 'o';
        }
        return newTurn;
    }


    public boolean checkIfWinner() {
        if (table[0][0] == table[1][0] &amp;&amp; table[1][0] == table[2][0] &amp;&amp; (table[0][0] == 'x' || table[0][0] == 'o')) {
            return true;
        } else if (table[0][1] == table[1][1] &amp;&amp; table[1][1] == table[2][1] &amp;&amp; (table[0][1] == 'x' || table[0][1] == 'o')) {
            return true;
        } else if (table[0][2] == table[1][2] &amp;&amp; table[1][2] == table[2][2] &amp;&amp; (table[0][2] == 'x' || table[0][2] == 'o')) {
            return true;
        } else if (table[0][0] == table[0][1] &amp;&amp; table[0][1] == table[0][2] &amp;&amp; (table[0][0] == 'x' || table[0][0] == 'o')) {
            return true;
        } else if (table[1][0] == table[1][1] &amp;&amp; table[1][1] == table[1][2] &amp;&amp; (table[1][0] == 'x' || table[1][0] == 'o')) {
            return true;
        } else if (table[2][0] == table[2][1] &amp;&amp; table[2][1] == table[2][2] &amp;&amp; (table[2][0] == 'x' || table[2][0] == 'o')) {
            return true;
        } else if (table[0][0] == table[1][1] &amp;&amp; table[1][1] == table[2][2] &amp;&amp; (table[0][0] == 'x' || table[0][0] == 'o')) {
            return true;
        } else if (table[2][0] == table[1][1] &amp;&amp; table[1][1] == table[0][2] &amp;&amp; (table[2][0] == 'x' || table[2][0] == 'o')) {
            return true;
        } else {
            return false;
        }
    }


    public boolean checkIfTie() {
        for (int i = 0; i &lt; 3; i++) {
            for (int p = 0; p &lt; 3; p++) {
                if (table[i][p] == ' ') {
                    return false;
                }
            }
        }

        return true;
    }


}


public class Main {

    public static void main(String[] args) {
        char player = 'o';
        int row, column;
        Scanner k = new Scanner(System.in);
        Game g = new Game();

        g.initializeGame();
        System.out.println("Game ready !\n");

        while (true) {
            player = g.changePlayer(player);
            System.out.print("\n" + player + " ,choose your location (row, column):");
            row = k.nextInt();
            column = k.nextInt();

            while (g.checkIfLegal(row, column)) {
                System.out.println("That slot is already taken or out of bounds, please try again (row, column).");
                g.displayBoard();
                row = k.nextInt();
                column = k.nextInt();
            }
            g.changeBoard(player, row, column);
            g.displayBoard();

            if (g.checkIfWinner()) {
                System.out.println("\nThe winner is " + player + " !");
                break;

            }
            if (g.checkIfTie()) {
                System.out.println("\nThe game is a tie !");
                break;
            }
        }


    }

}