Where did the data that is in that Memo field come from? It looks like it contains some special characters (so it is NOT blank). Did you copy it off of the Web or something?
It looks like it contains some formatting code.
Take a look at the following SQL code changes I made to your query (just change your Query to SQL View, and cut and copy this code in that window, then view the results):
Code:
SELECT Lista_cd.Recensione, Len([Lista_cd]![Recensione]) AS Length_Check, Left([Lista_cd]![Recensione],Len([Lista_cd]![Recensione])) AS Actual_Entry
FROM Lista_cd
WHERE (((Lista_cd.Recensione) Is Not Null And (Lista_cd.Recensione) Not Like "" And (Lista_cd.Recensione) Not Like ""));
Note the Length_Check calculated field I added is checking the length of your "Recensione" field. Note how it is not zero.
So, my "Actual_Entry" is return the actual value in that field, and you can see that none are blank. It looks like they have some formatting or HTML code included. That is what is causing your issues.