De thuiswerkplek is ergonomisch, zij het met beperkte bureauruimte.

Dutch often forms compounds by joining nouns together into one word.

• thuis = home
• werk = work
• plek = place/spot

So thuiswerkplek is a compound meaning a home workspace or work-from-home workstation.

This is very normal in Dutch. Where English often uses separate words, Dutch frequently combines them:

• huisdeur = front door / house door
• werkkamer = study / work room
• bureaustoel = desk chair

Every Dutch noun takes either de or het as its definite article, and werkplek is a de-word.

Because the head of the compound is plek, the whole compound keeps the same gender:

• de plek
• de werkplek
• de thuiswerkplek

A useful rule: in compounds, the last part usually determines the article.

Because ergonomisch is being used as a predicate adjective, after the verb is.

Compare:

• De thuiswerkplek is ergonomisch.
  Here the adjective comes after is, so it normally has no -e.

• De ergonomische thuiswerkplek
  Here the adjective comes before the noun, so it usually takes -e.

This is a very common Dutch pattern:

• De stoel is comfortabel.
• De comfortabele stoel

Zij het is a fixed, fairly formal expression meaning something like:

• albeit
• though
• though it is true that
• be it

In this sentence, it adds a limitation or reservation:

• De thuiswerkplek is ergonomisch, zij het met beperkte bureauruimte.

So the idea is: the workspace is ergonomic, although the desk space is limited.

It is mostly used in written or formal Dutch. In everyday speech, people would often choose something simpler, such as:

• maar met beperkte bureauruimte
• al is de bureauruimte beperkt

No. In zij het, zij is not the everyday subject pronoun.

The whole expression is an old-fashioned fixed construction based on the verb zijn. You do not need to analyze it as normal modern grammar word by word. The safest approach is to learn zij het as a single unit meaning albeit/though.

So although it looks like zij, it is not functioning like the ordinary pronoun in a sentence such as:

• Zij werkt thuis.

The comma marks zij het met beperkte bureauruimte as a kind of added comment or concessive phrase.

It works a bit like English:

• The workspace is ergonomic, albeit with limited desk space.

Because this part is an inserted qualification, Dutch normally separates it with a comma. That punctuation makes the sentence easier to read and shows that the second part is not a full main clause.

Because beperkte comes before the noun bureauruimte, so it is an attributive adjective. Attributive adjectives in Dutch usually take -e.

So:

• de bureauruimte is beperkt
  predicate adjective, no -e
• de beperkte bureauruimte
  attributive adjective, with -e

This contrast is extremely common:

• de tafel is groot / de grote tafel
• de stoel is zacht / de zachte stoel

Because met beperkte bureauruimte is a prepositional phrase, and bureauruimte is being used in a general, uncountable sense.

Here bureauruimte means something like desk space or space on the desk, which behaves more like a mass noun than a countable object. English does something similar:

• with limited desk space not necessarily
• with the limited desk space

Dutch therefore naturally says:

• met beperkte bureauruimte

If you wanted to refer to a specific, identifiable desk space, an article could appear in a different context, but in this sentence the general, article-less version is the natural choice.

Yes. It is made up of:

• bureau = desk
• ruimte = space

So bureauruimte means desk space or space at/on the desk.

Again, Dutch prefers compounds where English often uses separate words. Writing bureau ruimte as two words would be incorrect in standard Dutch.

Yes. Zij het sounds fairly formal and somewhat written. More everyday alternatives include:

• De thuiswerkplek is ergonomisch, maar de bureauruimte is beperkt.
• De thuiswerkplek is ergonomisch, maar met beperkte bureauruimte.
• De thuiswerkplek is ergonomisch, al is de bureauruimte beperkt.

The original sentence is perfectly correct, but it has a more polished, formal tone than the most common spoken Dutch.