Get Data from Excel: GhostSheet1, also defined Table vs raw data

The thing is your question doesn't really concern PowerBI:

When you export from Access to Excel it creates 2 things in Excel:

1) worksheet named after query/table you export

2) named ranged with only the used cells within that worksheet
I would use worksheet rather than range cause I don't know your process - when the data is updated you meay create a new file, update existing one, etc. - none of that is related to how Power BI handles it,

The guess is regarding your process, rather than what PowerBI will do - if you connect to worksheet it will extract all the cells with data, if you connect to range, it will only extract that range, it's very simple.