Mio fratello sa imballare i piatti meglio di me.

With singular close family members, Italian usually omits the article before the possessive:

• mio fratello = my brother
• mia madre = my mother
• tuo zio = your uncle

So mio fratello is the normal form here.

You usually do use the article with:

• plural family members: i miei fratelli
• modified family nouns: il mio fratello maggiore
• cases where you want special emphasis or a different nuance

So in this sentence, mio fratello is exactly what you would expect.

Sapere + infinitive means to know how to do something.

So:

• sa imballare = he knows how to pack
• not just he knows in the sense of knowing a fact

Compare:

• Mio fratello sa nuotare = My brother knows how to swim
• Mio fratello sa la risposta = My brother knows the answer

In your sentence, sa imballare i piatti means your brother has the know-how or skill to pack the plates.

Because sapere and potere mean different things.

• sapere + infinitive = to know how to do
• potere + infinitive = to be able to / to be allowed to

So:

• sa imballare i piatti = he knows how to pack the plates
• può imballare i piatti = he can pack the plates / he is able or allowed to pack them

Your sentence is about skill, not permission or simple possibility, so sa is the better choice.

Italian often uses the definite article where English would not.

Here, i piatti can mean:

• the plates in a specific situation, or
• more generally plates/dishes as the things being packed

Italian is much more comfortable than English with saying the + noun in these kinds of contexts.

So even though English might say pack plates, Italian naturally says imballare i piatti.

Imballare means to pack up, especially for:

• transport
• shipping
• moving
• protection

In this sentence, it suggests packing the plates in a careful, practical way so they can be moved without breaking.

It is a bit more specific than a general wrap. Depending on context, related verbs could be:

• impacchettare = to wrap up / package
• avvolgere = to wrap
• confezionare = to package, often more formally

For dishes or plates during a move, imballare sounds very natural.

Because meglio is the comparative form of bene.

• bene = well
• meglio = better

So:

• imballa bene = he packs well
• imballa meglio = he packs better

Just as English says better rather than more well, Italian says meglio rather than più bene.

In the sentence, meglio modifies the action imballare:

• sa imballare i piatti meglio di me = he knows how to pack the plates better than I do

Because after a preposition like di, Italian uses the stressed pronoun:

• me, not io
• te, not tu
• lui/lei, not egli/ella or subject forms

So:

• meglio di me = better than me
• meglio di te = better than you

That is why di io is not correct.

Meglio di me is very natural and common in everyday Italian.

It is a shorter way of saying something like:

• meglio di quanto faccia io
• meglio di come faccio io

These longer versions make the comparison more explicit:

• better than I do

So:

• Mio fratello sa imballare i piatti meglio di me = perfectly normal, idiomatic Italian
• Mio fratello sa imballare i piatti meglio di quanto faccia io = more explicit, a bit more formal or careful

Both are correct, but the shorter one is what many people would normally say.

Piatti can mean:

• plates
• dishes

In this sentence, because of imballare (to pack up), the meaning is almost certainly plates or crockery/dishes as physical objects.

It would not normally mean prepared food dishes here, because you do not usually pack those with imballare in this way.

The sentence is ordered in a very normal Italian way:

• Mio fratello = subject
• sa imballare = verb phrase
• i piatti = object
• meglio di me = comparison phrase

So the structure is basically: My brother knows how to pack the plates better than me.

Putting meglio di me at the end is natural because it clearly modifies the whole action imballare i piatti.

Other word orders are sometimes possible in Italian, but this version is the most straightforward and natural.

Yes. That is a very good way to understand it.

Literally, the sentence says:

• My brother knows how to pack the plates better than me

But in natural English, it often comes out as:

• My brother is better than I am at packing plates

So the Italian focuses on knowing how to do the action, but the overall idea is clearly about greater skill.