A lakodalom ültetési rendje kész.

A quick breakdown:

• A = the
• lakodalom = wedding celebration / wedding feast / reception
• ültetési = seating-, related to seating
• rendje = its order / arrangement / plan
• kész = ready

So the structure is roughly:

• A lakodalom ültetési rendje = the wedding’s seating plan
• kész = is ready

More literally, Hungarian is saying something like The wedding seating-order is ready.

Because Hungarian usually leaves out the verb to be in the present tense, third person singular when the predicate is a noun or an adjective.

So:

• A lakodalom ültetési rendje kész. = The wedding seating plan is ready.

This is completely normal Hungarian.

You would not normally add van here.

Not exactly.

• esküvő = the wedding ceremony
• lakodalom = the wedding celebration, especially the feast/reception/party

In real life, English wedding can cover both ideas, but Hungarian often separates them more clearly.

In this sentence, lakodalom makes good sense because a seating plan is especially associated with the celebration/meal part.

Because Hungarian uses a possessive structure here.

English says:

• the wedding’s seating plan

Hungarian expresses that by putting the possessive ending on the thing possessed:

• lakodalom ... rendje

So rendje means roughly its order/plan.

This is a very common Hungarian pattern:

• a ház teteje = the roof of the house
• a könyv címe = the title of the book
• a lakodalom ültetési rendje = the wedding’s seating plan

So the important point is: in Hungarian, the ending goes on the possessed noun, not on the possessor.

ültetési is an adjective-like form meaning related to seating.

It comes from:

• ültet = to seat someone
• ültetés = seating / the act of seating
• ültetési = seating-, related to seating

This -i ending is very common for making a noun into a descriptive form:

• fizetés = payment → fizetési = payment-related
• közlekedés = transport → közlekedési = transport-related
• ültetés = seating → ültetési = seating-related

So ültetési rend is basically seating arrangement/order.

Because the whole expression is one noun phrase, and Hungarian normally puts the article at the front of the whole phrase.

So:

• A lakodalom ültetési rendje = the wedding’s seating plan

This is normal. Hungarian does not need another article before ültetési rendje here.

A similar pattern:

• a ház teteje = the roof of the house
• a lány könyve = the girl’s book

Yes, it could.

Hungarian has two common ways to express the possessor:

1. Unmarked possessor

   • A lakodalom ültetési rendje kész.

2. Marked possessor with -nak/-nek

   • A lakodalomnak az ültetési rendje kész.

The second version can sound a bit more explicit, emphatic, or contrastive, depending on context.

In a simple neutral sentence, the version without -nak/-nek is perfectly natural.

Yes.

Both are natural, but the emphasis is a little different:

• A lakodalom ültetési rendje kész.
  Neutral: The wedding seating plan is ready.

• Kész a lakodalom ültetési rendje.
  This puts more focus on kész: The wedding seating plan is ready / done.

Hungarian word order is flexible, and it often reflects emphasis or information structure rather than a fixed English-style pattern.

It can suggest both, depending on context.

Here, kész most naturally means:

• ready
• completed
• done

So the sentence means that the seating plan has been prepared and is now available.

If you want to stress the idea of it got completed, Hungarian often uses elkészült:

• A lakodalom ültetési rendje elkészült. = The wedding seating plan has been completed.

But kész is very natural in the original sentence.

Yes, it is a normal expression for a planned seating arrangement.

It refers to the organized placement of people at tables or seats.

You may also see ülésrend, which can also mean seating plan or seating arrangement. The nuance depends on context, but ültetési rend is especially natural when people are being assigned places at an event such as a wedding.