Se la tablo estas plena de malnovaj notoj, mi ordigas ĝin kaj forĵetas tion, kio ne plu gravas.

Because plena means full, and in Esperanto plena normally takes de to show what something is full of.

• la tablo estas plena de malnovaj notoj = the table is full of old notes

So:

• plena = full
• de = of
• malnovaj notoj = old notes

The notes are not the direct object here. They are the content that fills the table, so Esperanto uses de, not the accusative -n.

Because both words are plural.

• noto = a note
• notoj = notes

In Esperanto, adjectives agree with the nouns they describe in number and case.

• malnova noto = an old note
• malnovaj notoj = old notes

So:

• malnova becomes malnovaj
• noto becomes notoj

Both get -j because the noun is plural.

Ĝin is the accusative form of ĝi, and it means it as a direct object.

Here, ĝin refers back to la tablo:

• la tablo = the table
• mi ordigas ĝin = I tidy it / I put it in order

Why accusative? Because ĝin is the object of ordigas.

A useful breakdown:

• ĝi = it
• ĝin = it, as a direct object

So Esperanto marks the object clearly with -n.

Ordigi means to put in order, to organize, or to tidy up.

It comes from:

• ordo = order
• ordigi = to make orderly / to organize

So:

• mi ordigas ĝin literally means something like I make it orderly
• in natural English: I tidy it or I organize it

The ending -as shows present tense:

• ordigas = organize / am organizing / tidy / tidy up

The prefix for- adds the idea of away, off, or gone from here.

• ĵeti = to throw
• forĵeti = to throw away

So:

• mi forĵetas tion = I throw that away

This prefix is very common in Esperanto. It often shows removal or movement away.

Examples:

• foriri = to go away
• forpreni = to take away
• forĵeti = to throw away

Because this part refers to a thing / whatever, not to a specific noun or person.

• tion = that, that thing
• kio = what / that which

So:

• tion, kio ne plu gravas = that which no longer matters / whatever is no longer important

Why not kiu?

• kiu usually refers to a specific noun already mentioned, or means which one / who
• kio is used for what, that which, or something less specifically named

Here, the speaker means the stuff that doesn’t matter anymore, not a particular named noun. So kio is the natural choice.

Tion is the direct object of forĵetas.

Structure:

• mi forĵetas tion = I throw that away
• kio ne plu gravas describes what tion is

So the full idea is:

• I throw away that which no longer matters

You can think of tion as a placeholder:

• I throw away that ...
• and then the relative part explains which that: ... which no longer matters

Because it is the object of forĵetas, it has -n.

Literally, it means:

• kio = what / that which
• ne plu = no longer
• gravas = matters / is important

So the phrase means:

• what no longer matters
• that which is no longer important

It functions like a relative clause describing tion.

Ne means not.

Plu adds the sense of any longer / anymore / further.

So:

• ne gravas = it does not matter / it isn’t important
• ne plu gravas = it no longer matters / it isn’t important anymore

This is a very common expression in Esperanto.

Examples:

• Mi ne plu laboras tie. = I no longer work there.
• Ŝi ne plu loĝas ĉi tie. = She doesn’t live here anymore.

So ne plu is the natural way to say no longer.

Because gravi means to matter or to be important, and it does not need a direct object here.

• ĝi gravas = it matters
• tio ne plu gravas = that no longer matters

In this sentence, kio is the subject of gravas:

• kio ne plu gravas = what no longer matters

So nothing is missing. The verb works on its own, much like English matter.

The ending -as is the present tense in Esperanto.

Here we have:

• estas = is
• ordigas = organize / tidy
• forĵetas = throw away
• gravas = matters

Esperanto often uses the present tense for:

• habitual actions
• general truths
• repeated situations
• vivid description

So this sentence can mean something like:

• If the table is full of old notes, I tidy it and throw away what no longer matters.

That sounds like a general habit or routine.

The first comma separates the if-clause from the main clause:

• Se la tablo estas plena de malnovaj notoj, mi ordigas ĝin...

This is very normal in Esperanto.

The second comma marks the start of the clause that explains tion:

• tion, kio ne plu gravas

That clause means that which no longer matters.

So the commas help show the sentence structure clearly:

1. condition: Se ...
2. main action: mi ordigas ... kaj forĵetas ...
3. explanatory clause: kio ne plu gravas

In principle, noto can mean a note in more than one sense, depending on context. But here, because the table is full of old notes and the speaker is sorting and throwing things away, it clearly means written notes / papers / memos.

So the context tells you which meaning is intended.

Because Esperanto does not always use an article where English might.

• la tablo = the table, a specific table
• malnovaj notoj = old notes, notes in general

The sentence does not need to say the old notes. It just says the table is full of old notes.

If you said la malnovaj notoj, that would point to a specific set of old notes already known from context.

So:

• plena de malnovaj notoj = full of old notes
• plena de la malnovaj notoj = full of the old notes

Both are possible in the right context, but the version in the sentence is more general and natural.

Yes, in this sentence se works just like English if.

• Se la tablo estas plena de malnovaj notoj... = If the table is full of old notes...

It introduces a condition.

Very common pattern:

• Se ... , mi ...
• If ... , I ...

Examples:

• Se pluvas, mi restas hejme. = If it rains, I stay home.
• Se mi havas tempon, mi legas. = If I have time, I read.

So this is a straightforward use of se.