If I've understood correctly, you want to run an update query on several tables. For this to work, all of your tables would have to have identical field names - which seems unlikely.
Anyway, if you do want to do this, the following method may suit:
+ declare a variable
+ use something like an inputbox to prompt the user for the table name and assign the value entered to the variable
+ construct your SQL using the variable
dim sInput as string
mySQL="update table " & sInput & " set [FIELDNAME]." & sInput & "=<VALUE>"