Aquazone wrote
Can anyone tell me if I can delete the folders cache, locks, meta, tmp and index safely?
You can safely delete the contents of most of those folders. The cache, locks, and index will get rebuilt. But some of the meta data will get lost and it won't be possible to get all of it back.
But that might be exactly what you want? In case you also want to get rid of all the history of the page (including old revisions), then you should also delete the content of the meta folder together with the attic folder.