Višak i manjak su u tabeli.

Because the subject is compound: višak i manjak = surplus and deficit / excess and shortage. Two nouns joined by i (and) count as plural, so Serbian uses su, the 3rd person plural form of biti (to be).

• je = is
• su = are

So:

• Višak je u tabeli. = The surplus is in the table.
• Višak i manjak su u tabeli. = The surplus and deficit are in the table.

They are in the nominative case, because they are the subject of the sentence.

• višak = nominative singular
• manjak = nominative singular

Together, they form a plural subject, which is why the verb is su.

Because the preposition u usually takes the locative case when it means in and shows location.

Here, u tabeli means in the table / in the chart, so tabela changes to its locative singular form:

• nominative: tabela
• locative: tabeli

So:

• u tabeli = in the table/chart

Tabela is a feminine noun ending in -a. For many feminine nouns of this type, the locative singular ends in -i.

So the pattern is:

• tabela → nominative singular
• u tabeli → locative singular

This is a very common pattern in Serbian:

• škola → u školi
• soba → u sobi
• tabela → u tabeli

Serbian has no articles, so it does not have direct equivalents of the or a/an.

That means višak i manjak can mean things like:

• the surplus and deficit
• surplus and deficit

The exact English translation depends on context, but Serbian simply does not mark this with an article.

Yes. Serbian word order is fairly flexible, although some versions sound more natural in certain contexts.

The basic sentence is:

• Višak i manjak su u tabeli.

But you could also say:

• U tabeli su višak i manjak.

This version puts more emphasis on where they are: in the table.

Both are grammatical. The difference is mostly about focus and style, not basic meaning.

Yes. In this sentence, i is simply the conjunction and:

• višak i manjak = surplus and deficit

Serbian i can also sometimes mean also / too in other contexts, but not here. Here it is clearly joining two nouns.

Because Serbian normally uses u for something being in a container, place, list, text, table, chart, and so on.

So:

• u tabeli = in the table/chart

Using na would usually suggest on a surface, which is not the intended meaning here.

This is similar to how Serbian often says:

• u knjizi = in the book
• u tekstu = in the text
• u tabeli = in the table/chart

Here they are nouns.

• višak = surplus, excess
• manjak = deficit, shortage, lack

They are acting as the things being talked about, not describing another noun. That is why they can serve as the subject of the sentence.

Usually yes, but in many contexts it may be more natural in English to say chart, table, or spreadsheet table, depending on what is meant.

So u tabeli could mean:

• in the table
• in the chart

If the sentence is about data, numbers, accounting, or a document, table or chart is often the best interpretation.

Because of both the form and the meaning.

With u:

• u + locative usually shows location: in
• u + accusative usually shows movement into: into

Here we have:

• u tabeli → locative
• so the meaning is are in the table, not go into the table

Compare:

• Podaci su u tabeli. = The data are in the table.
• Unesite podatke u tabelu. = Enter the data into the table.

Yes. Each noun is individually singular:

• višak = singular
• manjak = singular

But when Serbian joins them with i (and), the whole subject becomes plural, so the verb agrees in the plural:

• Višak i manjak su...

This is the same idea as in English:

• The cat and the dog are...

Each noun is singular, but together they form a plural subject.

A couple of things may stand out to English speakers:

• š is pronounced like sh in ship
• j is pronounced like y in yes

So roughly:

• višak ≈ vee-shak
• manjak ≈ mahn-yak

These are only rough guides, but they help with reading. Serbian spelling is generally quite phonetic, so letters are pronounced more consistently than in English.