Import the CSV file data values as numeric [In your notebook they have been imported as strings] :
Import["C:\\Users\\User\\Desktop\\Prova3.csv", "Numeric" -> True]
Or use SemanticImport command. Please check the documentation for more information.
Alternatively, you can still plot the values in your notebook:
ListPlot@ToExpression[Flatten[#, 1] & /@ (StringSplit /@ lalla)]