When filling a form, can the entered data be stored in more than one tables? How?

Yes on your second table enter a new field under the lookup section and then point it to the original table and the filed you want to duplicate, then when you enter the data into the form it will go to both tables. http://www.access-programmers.co.uk/ubb/smile.gif

Generally speaking, It should not be necessary to duplicate data between tables (The obvious exception is addresses but even this can be looked up from a post/zip code). Have a look at your table structure to find out why you are duplicating data and if it can be avoided.