Access inherently grows over use. This is fact. Periodically, you will have
to compact the database to reduce the size. This has nothing to do with the
queries themselves, but the data that the queries return. As the queries
run, different amounts of records are returned. This action will create
'bloat' within the database. Once you run compact/repair on the database, it
removes that 'bloat'. The degree to which it compacts may not result in the
file returning to the same size. So remember, even after compacting the file
may be slightly larger than the last compact.
Other than this, when you designed your tables, I take it you didn't just make all the test field size 255 - you scoped them correctly?
HTH
Dave