This sounds like a structural design issue. Having two tables that differ by only one field is not only wasteful but sets you up for maintenance issues in the future. So... supposed that you make the copy of BBB plus one more field. Now, two days later you have to come back to update some data in BBB. Are you going to have to update the data in the new table as well?
You claim to be a novice, so that suggests to me that you need to understand a couple of ideas.
1. Read up on "database normalization." I wrote it that way because in a general web search, you have to use both words. There are other types of normalization in math, politics, chemistry, and maybe a couple of other subjects that slip my mind. If you do that search within this forum with the SEARCH feature in the top row next to your login name, you can drop "database" because this IS a database forum.
2. Read up on queries AFTER you learn about normalization. It is possible to use a JOIN query to put tables together temporarily so that you can use their combined information. And here's an important thing to know: Access allows you to use queries in most places that normally might need tables. Access does not "care" most of the time about the source of records. It only cares that it HAS a source. Granted, there are a few cases where a query has trouble as a .RecordSource for things that do updates. But for display purposes, queries are your friends.
How this applies to you is that if there is a relationship between two data sets, you can often JOIN them together and use them as one source. Like having your BBB table and having another table that includes this extra field. Then normally, if you update BBB, the query that joins your data sets will pick up the new data next time you open that query. And you only have one place to maintain the content. (Which is why I told you to read up on normalization first - it is a method to allow you to minimize duplication of data in a database.)