Default to data in a different table?

I know this might seem technically wrong and therefore, I haven’t found
advice on how to do it on these postings. I have an Access 03 table
“EventTable1� with fields “StartTime� and “EndTime�. These times are the
actual times of our events. I have another table “StaffTable1� with fields
�ActualStartTime� and “ActualEndTime�. I want to track all these times in
the table and want the actual start/end time fields to default to the
start/end time fields. Many times they’ll be the same, but sometimes they
won’t. Any simple ways of doing this using the default value in table design?

Thank you!