This usually means youre not actually querying the same schema you think you are. SHOW TABLES; only shows tables in the currently selected database. If Workbench reconnects or the default schema changes, SELECT * FROM mytable; may be running against another database, which explains the 1146 error.

Run:

SELECT DATABASE();

and confirm it matches the schema where you created the table. Or fully qualify it:

SELECT * FROM database.mytable;
DROP TABLE database.mytable;

Another common cause on Windows is case sensitivity. The table might have been created as MyTable and you're querying mytable. Even on Windows, depending on lower_case_table_names, mismatched case can cause weird behavior.

Worst case scenario: the .frm file exists but the underlying InnoDB metadata is corrupted, so it shows up in SHOW TABLES but cant actually be accessed. If thats the case, check SHOW ENGINE INNODB STATUS; and the MySQL error log. If it turns out to be dictionary corruption, you may need to drop the orphaned table files manually or use a recovery tool like Stellar Repair for MySQL to extract data before recreating the table.