Мама подала на стол борщ и хлеб.

Because подать can mean to hand/give, but with food and the phrase на стол, it very often means to serve.

So:

• подать = to give/hand over, or to serve
• подать на стол = to serve food to the table

In this sentence, Мама подала на стол борщ и хлеб means that Mother served borscht and bread.

Also, подала is the past tense feminine singular form, matching мама.

Russian past tense changes to match the gender and number of the subject.

Here the subject is мама, which is:

• singular
• feminine

So the verb must be подала.

Compare:

• папа подал = Dad served
• мама подала = Mom served
• родители подали = The parents served

This is a very common feature of Russian past tense.

Because мама is the subject of the sentence, so it stays in the nominative case.

The sentence answers the question Who served the food?
Answer: мама

So:

• мама = nominative, the doer of the action
• маму would be accusative, usually used when mom is the object

For example:

• Мама подала борщ. = Mom served borscht.
• Я вижу маму. = I see Mom.

This is a very important Russian pattern:

• на стол = onto the table / to the table → direction, movement toward a destination
• на столе = on the table → location, where something already is

Here the idea is that the food is being brought/served to the table, so Russian uses:

• на + accusative → на стол

Compare:

• Мама поставила тарелку на стол. = Mom put the plate onto the table.
• Тарелка стоит на столе. = The plate is on the table.

So подала на стол focuses on the act of serving food to the table.

They are the direct objects of the verb, so they are in the accusative case. But for many inanimate masculine nouns, the accusative singular looks exactly like the nominative singular.

So:

• борщ → accusative борщ
• хлеб → accusative хлеб

That is why they look unchanged.

Compare with an animate masculine noun:

• Я вижу стол. = I see the table.
  (стол stays the same because it is inanimate)
• Я вижу брата. = I see my brother.
  (брат changes to брата because it is animate)

Yes, it is a very common expression when talking about food.

Подать на стол means:

• to serve
• to bring out for eating
• to put food on the table for a meal

So learners should recognize it almost as a set phrase.

For example:

• подать ужин на стол = to serve dinner
• подать суп на стол = to serve soup

It is more natural in this context than translating each word too literally.

Подать is perfective.

That means it presents the action as:

• completed
• whole
• finished as a single event

So подала suggests that Mom served the borscht and bread as a completed action.

Its imperfective partner is usually подавать.

Compare:

• Мама подавала борщ каждый день. = Mom used to serve borscht every day.
  (repeated/process idea)
• Мама подала борщ. = Mom served the borscht.
  (completed action)

This is one of the most important verb distinctions in Russian.

Russian has no articles.

So борщ can mean:

• borscht
• the borscht
• some borscht

And хлеб can mean:

• bread
• the bread
• some bread

The exact meaning comes from context, not from words like the or a.

That is why one Russian sentence can often be translated into English in more than one natural way.

Yes. Russian word order is flexible, and changing it usually changes emphasis, not the basic meaning.

This sentence:

• Мама подала на стол борщ и хлеб.

is a natural neutral way to say it.

Other possibilities are possible too, for example:

• Мама подала борщ и хлеб на стол.
• Борщ и хлеб мама подала на стол.

These alternatives may sound more marked or put emphasis on different parts.

In general:

• earlier in the sentence = often more known/topic information
• later in the sentence = often newer or emphasized information

But the original sentence is a good standard pattern.

Because и simply joins two objects of the same verb:

• борщ
• хлеб

This is just like English borscht and bread.

Russian normally does not use a comma before и when it connects two items in a simple list.

So:

• борщ и хлеб = borscht and bread

No comma is needed.

Sometimes yes, but the meaning is a little different.

• подала на стол = served, brought out for the meal
• поставила на стол = put on the table, placed on the table

So подала sounds more natural if the focus is on serving food.
Поставила focuses more on the physical act of placing something somewhere.

Compare:

• Мама подала на стол борщ. = Mom served borscht.
• Мама поставила тарелку на стол. = Mom put the plate on the table.

So in this sentence, подала is the better choice.

Usually here it means bread in a general food sense, not necessarily one whole loaf.

In Russian, хлеб can mean:

• bread as food
• a loaf of bread, depending on context

In a meal context like this sentence, English will usually just say bread.

If Russian wants to be more specific, it can add another word, for example:

• буханка хлеба = a loaf of bread
• кусок хлеба = a piece of bread

So in this sentence, хлеб is most naturally understood as bread served with the meal.