Едва мама открыла контейнер, как все начали есть шашлык.

In this sentence, едва means something like hardly / barely, but in the full pattern едва ..., как ... it is best translated as as soon as or no sooner ... than.

So the idea is:

• Едва мама открыла контейнер, как ...
• As soon as / No sooner had Mom opened the container, than ...

It emphasizes how quickly the second action happened after the first one.

This is a common Russian construction:

• едва ..., как ...

It links two actions very tightly in time. The second action happens immediately after the first.

A rough English parallel is:

• No sooner had X happened than Y happened

So here:

• Едва мама открыла контейнер, как все начали есть шашлык.

means that right after the container was opened, everyone started eating.

Russian also often uses similar patterns such as:

• как только ...
• лишь только ...

But едва ..., как ... sounds a bit more literary or expressive.

Because the subject is мама, which is feminine singular.

In the Russian past tense, verbs agree with the subject in:

• gender in the singular
• number in the plural

So:

• мама открыла = Mom opened
• папа открыл = Dad opened
• родители открыли = the parents opened

The ending -ла shows feminine singular past tense.

Because начали есть means started eating, not simply ate or were eating.

This is important for the meaning of the sentence. The speaker wants to focus on the moment when the eating began, immediately after the container was opened.

Compare:

• все начали есть шашлык = everyone started eating shashlik
• все ели шашлык = everyone was eating / ate shashlik

So начали есть matches the idea of a sudden reaction.

Because начать means to begin / to start, and in Russian it is followed by an infinitive.

So:

• начать есть = to start eating
• начать говорить = to start speaking
• начать работать = to start working

This is very similar to English start + -ing / start + infinitive, except Russian uses the infinitive form directly.

Because есть in the sense of to eat normally takes the accusative case.

The noun шашлык is:

• masculine
• singular
• inanimate

For many inanimate masculine nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• nominative: шашлык
• accusative: шашлык

That is why the form does not change.

If it were an animate masculine noun, the accusative would often look different. For example:

• кот → вижу кота

But with шашлык, nominative and accusative are the same.

Both finite verbs here are perfective:

• открыла from открыть
• начали from начать

That makes sense because both actions are viewed as single completed events:

• Mom opened the container
• everyone started eating

But the infinitive есть is imperfective.

This is normal after phase verbs like:

• начать = start
• продолжать = continue
• перестать = stop

After these verbs, Russian usually uses the imperfective infinitive, because the focus is on the beginning, continuation, or end of an activity.

So:

• начали есть is the natural form

Because Russian has no articles.

So Russian does not have direct equivalents of English a, an, and the.

That means:

• мама can mean Mom, the mother, or my mother, depending on context
• контейнер can mean a container or the container
• шашлык can mean shashlik or the shashlik

The exact meaning comes from the situation, context, and word order, not from articles.

The word order in this sentence is natural and neutral:

• Едва мама открыла контейнер, как все начали есть шашлык.

Russian word order is more flexible than English word order, but it is not random. Here the structure clearly separates the two clauses:

1. Едва мама открыла контейнер
2. как все начали есть шашлык

This order sounds smooth and standard.

You could change word order in some contexts for emphasis, but this version is probably the most natural for a learner to use.

Yes. Контейнер is a normal Russian noun and is widely used.

It is a masculine inanimate noun:

• контейнер
• контейнера
• контейнеру
• etc.

In everyday speech, it can refer to many kinds of containers, including food containers, depending on context.

So открыла контейнер sounds perfectly normal.

Yes, absolutely.

For example:

• Как только мама открыла контейнер, все начали есть шашлык.

This also means as soon as Mom opened the container, everyone started eating shashlik.

The difference is mostly stylistic:

• как только = very common, neutral, everyday
• едва ..., как ... = a bit more expressive, sometimes a little more literary, and it highlights how immediate the second action was

So both are correct, but they have slightly different flavor.