I have a workbook that is accessed by a lot of users using different
spec machines. The workbook is periodically updated with data added
from different sources in an automated fashion using macros.

Of late the file has grown from 23megs to a whopping 93megs, although
as far as I can tell the new worksheets and charts added should
*logically* constitute no more than a 20% increase in size from the
previous incarnation, and anyway most of the data is stored as values
(i.e. formulas removed after processing).

This growth in file size has resulted in increased loading times and
system slowdowns whenever the workbook is accessed.

Note that one thing that I have done recently is move a handful of
charts so that they are located inside worksheets rather than in their
own tabs. Could this have had such a marked effect on increasing the
size?

My questions are:
(1) Is there anything I can do to make the file smaller
(2) Why has the file grown so big all of a sudden
(3) What can I do to improve Excel's performance? I have 2 gigs of ram
on my machine and a really fast processor and still suffer from
annoying slowdowns when working with big files (and am pretty sure I do
not have viruses/spyware on my machine)

Any thoughts would be extremely appreciated!