const myMap = new Map([
['key1', {a:1,b:2}],
['key2', {a:1,b:2}],
['key3', {a:1,b:2}]
]);
const myArray = Array.from(myMap.entries());
console.log(myArray); // [['key1', 'value1'], ['key2', 'value2'], ['key3', 'value3']]
myArray[0][1] = "test"
console.log(myArray[0][1])
// const myArray1 = Array.from(myMap.entries());
console.log(myMap);