I suppose the best answer is "it depends" :)

I'm not sure about just opening a table, I think some information is cached but I'm not sure what the criteria are. If SET DELETED is ON then I would expect the index on DELETED() to be scanned (if you have one) to build the bitmap to optimise further operations.

As much of the index as necessary, when executing the query.
Now because you may have been adding records, resulting in the tags being pretty much spread through the whole index file - it may well read the whole index.

As much of the table as possible, when BROWSEing a table.
That's going to depend on your machine's memory. VFP tries to cache as much as possible for future access.


Now views, you can specify NODATAONLOAD which creates an empty structure (sort of WHERE 1=0 or WHERE .F.) which makes them pretty efficient. That will optimise to just creating the structure - I would guess by reading the table header.