Sur la tablo kuŝas plumo, krajono kaj malfermita kajero.

Esperanto allows fairly flexible word order. Starting with Sur la tablo puts the location first, a bit like On the table lies... in English.

So this sentence is natural and slightly scene-setting:

• Sur la tablo kuŝas plumo, krajono kaj malfermita kajero.

A more neutral order would also be possible:

• Plumo, krajono kaj malfermita kajero kuŝas sur la tablo.

Both are grammatical. The original just emphasizes the place first.

Kuŝi means to lie or to be lying/resting, often in a horizontal position. For objects, it can mean they are lying somewhere physically.

So:

• estas = simply is/are
• kuŝas = lies / is lying

Using kuŝas makes the image more vivid. It suggests the pen, pencil, and notebook are physically lying on the table, not just existing there.

La is the definite article, meaning the.

Here, la tablo means the table, presumably a specific table already known from the situation or context.

But plumo, krajono kaj malfermita kajero are presented as indefinite items:

• a pen
• a pencil
• an open notebook

So Esperanto is working much like English here:

• on the table
• a pen, a pencil, and an open notebook

There is no direct object here, so no accusative -n is needed.

In this sentence:

• plumo, krajono kaj malfermita kajero are the things that are lying there
• sur la tablo tells the location

Also, sur already marks place, so la tablo stays without -n because this is a static location, not motion.

Compare:

• Sur la tablo kuŝas libro. = The book is lying on the table.
• Mi metas la libron sur la tablon. = I put the book onto the table.

In the second sentence, tablon gets -n because it shows direction/movement onto the table.

Because Esperanto verbs do not change according to number or person.

So the present tense ending is always -as:

• mi kuŝas
• li kuŝas
• ili kuŝas

That means the same verb form is used whether the subject is singular or plural. This is very different from English, where you have lies vs. lie.

Malfermita is an adjective meaning opened or open.

It comes from:

• fermi = to close
• malfermi = to open
  (mal- gives the opposite meaning)
• malfermita = opened / open

More technically, it is a participial adjective, but for a learner it is enough to understand that it behaves like a normal adjective here:

• malfermita kajero = an open notebook

Because of where it is placed.

In:

• plumo, krajono kaj malfermita kajero

the adjective malfermita stands directly with kajero, so it describes only the notebook.

A reader naturally understands:

• a pen
• a pencil
• an open notebook

If you wanted an adjective to apply to more than one noun, you would usually make that clearer in the wording.

The usual, most neutral order is adjective + noun:

• malfermita kajero

But Esperanto can also place the adjective after the noun:

• kajero malfermita

That is grammatical, but it is less neutral and may sound more literary, emphatic, or stylistically marked. For ordinary usage, learners should usually prefer malfermita kajero.

Yes. Even though the Esperanto sentence uses kuŝas, the overall meaning can often be expressed in English as:

• There is a pen, a pencil, and an open notebook on the table.

A more literal translation would be:

• On the table lie a pen, a pencil, and an open notebook.

So the Esperanto sentence combines both existence and physical position.

No. Sur la tablon would suggest direction toward the table, not location on it.

With sur:

• sur la tablo = on the table, at rest
• sur la tablon = onto the table, toward the table

Since the objects are already resting there, sur la tablo is the correct form in this sentence.

Yes. Esperanto does not need a special dummy subject like English there.

English often says:

• There is a pen on the table.

Esperanto simply says:

• Sur la tablo kuŝas plumo.

That is a complete normal sentence. The verb kuŝas is the main verb, and plumo, krajono kaj malfermita kajero are the things doing that action/state.

Kaj means and.

In this sentence it links the last two items in the list:

• plumo, krajono kaj malfermita kajero

So the list is:

1. plumo
2. krajono
3. malfermita kajero

This works like normal English listing: a pen, a pencil, and an open notebook.