It depends. You back up your tables or db's before you try anything.
Does table1 contain records that are not in table2, but everything in table2 is in table1? If so, you should be able to create a query that appends all the records from 1 to 2. Any that violate the primary key will simply not be added. If you do not have a primary key, you will duplicate records.
If the answer to the question is no (tbl1 and tbl2 each contain records that are not in the other, then one approach would be to separately append tbl1 and tbl2 records into a new temp table. Then append these records back into ONE of the other tables after clearing it out. You could create an "unmatched records" query using the wizard, but I'm not sure what you'd do with the results as it will not tell you which table is missing which records.
However, if the records that are common between them are not identical, then you have a bigger problem. You will also need to perform an update query using one as the source and the other as the updated, but if you do not know which is the "master", then which ones values are you going to force upon the other? If this is going to be a recurring issue, you are doing something wrong or not doing something you should, or you are not using replication when you probably should be.
