Help with data load

Hello All,

Would require the best way to manage data loading.
I have got a model where i need to load data monthly and the data does not have the date,but then it would be possible to get the
date stamp from the sytem when loading so if i load it in april 2021 i could set a column with data for date to april.
The data is in an excel in a folder
Now if i want to load for next month MAY and the coming months how do i go about and append this data to the already existing April data.
Name of the files would be the same.The files would come into the folder in the mid of month.

Thanks