Learn Italian: Mi incarta del salame sottovuoto e delle patatine? - Can you wrap some vacuum-packed salami and some potato chips for me?

The partitive article combines di with the definite article, and it must match the noun. Salame is being treated as a masculine singular, uncountable mass here, so it takes del (di + il). Patatine is feminine, plural, and countable, so it takes delle (di + le). Both translate to "some" in English.

Is it strictly necessary to use del and delle here, or could I just say Mi incarta salame e patatine?

While dropping the partitive article isn't strictly ungrammatical, using del and delle is much more natural and common in everyday spoken Italian for requests like this. Without the partitive articles, the sentence sounds a bit abrupt or overly general, almost like "Wrap salami and chips for me" rather than asking for a specific, undefined quantity.

If the translation is "Can you wrap", why does the sentence use the third-person verb incarta instead of the second-person incarti?

The speaker is using the formal Lei (you), which takes the third-person singular verb conjugation. This is the standard, polite register to use when addressing a shopkeeper or deli worker in Italy. Mi incarta literally means "Does You (formal) wrap for me?".

Would the ending of sottovuoto change if we asked for multiple vacuum-packed items?