Dmitry,
If you have a stable network environment 4 memo fields really isn't any riskier then 3 memo fields. If you are that worried make sure you have a reliable backup solution in place.
>I am concerned about something.
>
>I have to add a memo field to a table that already has 3 memo fields. The table is now about 300,000 records and will probably grow to a million. I am concerned that the table might become susceptible to corruption having too many memo fields.
>
>Is my concern justifiable?