Sounds like your database structure is flawed. Generally, You should not
have multiple tables with the same fields. What is in your table? This can
almost always be accomplished by having one tale with one additional field
to define the "type" or record.
If your tables each refer to a different branch office, for example, you
could combine them into one and add an "office" field. Your queries,
reports, and forms could then use this field to limit the records returned.
IF you did this same scenario with a different table for each office, then
you would have to add a brand new table everytime your company grew. You'd
also have to create union queries and jump through other hoops if you ever
wanted to see combined reports. To then sum these by office would be even
harder.
It is likely that your structure could easily be changed to correct this and
save you many many headaches down the road.