it usually means that no table exists in the default database with the given name. In some cases, it may be that the table does exist but that you are referring to it incorrectly. Maybe your database and table names are case sensitive if they are located on a file system that has case-sensitive file names. Or perhapsall references to a given table within a query must use the same lettercase.
Use SHOW TABLES to check which tables are in the default database.
Well, if you are sure that table is exist and you write its name exactly such it should be, then I suppose something wrong with the database, it can be seriously corrupt. And in this case you need a professional help. This tool must help at any rate - Recovery Toolbox for MySQL https://mysql.recoverytoolbox.com/