not currently - any .xlsx file is treated as unstructured at the moment.  since there can be multiple worksheets with different structures, or no repeating structure at all.

at some point some structure analysis will be possible for excel files.

for the 2nd part of the question - there is no wildcard filtering for filesystem contents at the moment

yes - we see use cases where just documenting that a file exists, and it could also be used/shown in lineage without expanding the structure can be useful