Hi,
If your goal is to load the sharepoint data to power BI, why not use it as a datasource in power bi and schedule refresh accordingly?
create a datetable in powerbi and map it with your month column in teh SP list.
To answer your flow question:
try using "when an item is created in the list" trigger. this will start your flow.
Then do your next actions. For example, "Get items" action and then "apply to each" to add to your dataset.
if your dataset is sql("insert Row" action reuires premium license for sql actions) or anyother datasource.
Thanks,
Sravan