Yes, you can use 2D array. Set array width to the number of users, height to the number of values you need to store. Note that indices in arrays are 0-based. For example, if you need to set first user name to "John", do:
Array Set at X=0, Y=0, Value="John"
To set level 10 score for player number 5:
Array Set at X=4, Y=10, Value=score
You can save the entire array in Local Storage if needed using Array.AsJSON, and load it back using "Array set from JSON".