I would suggest that you make the first column of your result table by copying the first column of items from each list into one column so you have one list of all the variables, then you can perform a Remove Duplicates from the Data menu... you can then sort, if necessary,

Then you can do a Vlookup to each original table to find the matches, if any.

So if original table 1 is in A:C and your second table is in F:H and your "non-duplicate" list is in column K, then in K2, enter =IFERROR(VLOOKUP(K2,$A$2:$B$11,2,0),"--") and copy down, and in L2

=IFERROR(VLOOKUP(K2,$F$2:$H$11,2,0),"--")

you may need to replace the commas with semicolons and translate the functions to Italian.