tejap - the question betrays an Excel solution somewhere in the recent history of whatever you are trying to do. In Excel, that "fill-in" is automatic, or nearly so. In Access? Not so much, because tables don't have a well-defined "before" and "after" record. For complex reasons, Access tables have no particular or predictable order at all. Queries, on the other hand, can impose order on the chaos.
If you are manually entering data into a datasheet view of a table or query, you can use shortcut keys. See, for example,
https://www.fmsinc.com/microsoftaccess/Forms/shortcut_keys.htm
In that case <CTRL><'> (control apostrophe) brings down the value from the previous record's corresponding field. The article shows you a couple of other shortcut sequences as well, and they are good to remember.
Be aware that "datasheet view" is an Access "default form" that imposes order based on how it is viewed. If there is no primary key and no index in the table, however, there is no guarantee that if you close datasheet view and then open it again on another day that you would get the same order, particularly if any updating of that table has occurred in the interim.
If you are manually entering data in a form of your own making, then code in your form could be made to remember the most recent value entered for a particular field and would allow you to define a way to select that value. You would probably need to use some VBA event code to make that happen.