var table = [];

​

for(var i = 0; i <= 50; i++){

  var row = []

  table.push(row)

  for(var x = 0; x <= 12; x++){

    row.push(i * x)

  }

}

​

var one = prompt('enter a number')

var two = prompt('enter a second number to multiply it by')

​

console.log(one + ' x ' + two + ' = ' + table[one][two])

​