However, now the bad news. You can password protect a table only through a lot of gyrations.
Basically, you need to build a security schema that describes what roles each authorized user will take. These roles will become your user groups.
Assign rights according to the groups. Don't EVER assign rights according to an individual user, possibly expect yourself as DBA.
Now, to protect a table...
Give the users Read but not Update/Insert/Delete on the table.
Then build a form based on a query. Perhaps you should also HIDE the query. Now code up the form to have some strict sanity checking with field validation criteria. There is an attribute on the query that lets you choose whether the query's rights come from the user or the query's owner. In this case, you want the rights to come from the owner.
Now, here is what happens. The users can open the table but if they do so directly, they cannot change anything. If they COULD open the query directly, they could change whatever the query shows them. If the query is activated by a form, you can put field-level checks on the form.