“List all the things”, definitely.

With an undertone of ‘if anything’ thrown in. And of course it’s not clear whether you’re talking about the last 7 days, or the last calendar week, context would be everything there.

Also, it’s not the perfect, it’s the passé composé. Just saying :-).

It is neither "all the things" nor "(just) one thing".

The question is not specific about the amount of information asked so should be understood to mean "what noteworthy thing(s) did you do last week on the computer?".

La semaine dernière always means "last calendar week", never the previous seven days just like l’année dernière means 2017 if we are in 2018, not the last 365 days¹.

La semaine dernière doesn’t mean "one week ago" although "one week ago" necessarily occurred la semaine dernière. La semaine dernière can mean anything between "any time belonging to the previous calendar week" and "during the whole previous week".

Note also that semaine is often only a period of five days, Monday to Friday, the whole week being the concatenation of semaine and week-end. Unlike in the US and many countries, Sunday is generally considered the last day of the week in France.

Tell me one thing you did one week ago on the computer.

would translate to:

Dis-moi une chose que tu as faite sur l’ordinateur il y a une semaine.

while:

List all of the things you have done within the last week on the computer.

would be:

Dis-moi (or fait-moi la liste de) tout ce que tu as fait sur l’ordinateur (durant / au cours de) la semaine dernière.

If you ask about the current ending week, not the previous one, you might ask:

Dis-moi tout ce que tu as fait sur l’ordinateur cette semaine.

¹_{One exception is when referring to schools/universities where the year, noted for example 2018-2019, starts in September and ends in June or early July}

Qu’as-tu fait la semaine dernière sur l’ordinateur?

In rendering this the past simple must be used.

• What did you do on the computer last week?

If you had used “this week” instead of “last week” then you would have had to use the present perfect as the action would not have been finished at the time of talking.

• What have you done this week on the computer?

As I understand

“Tell me one thing you did one week ago on the computer.”,

where “one” is stressed, the person who is speaking wants to know one single thing from possibly many things that have been done and this context is not common. A translation would be as follows.

• Dites moi une seule des choses que vous avez faites sur l’ordinateur il y a une semaine.

This English sentence cannot be confused with the next, which context is found often enough; the time of the action in the past is punctual (…you did one week ago…) but it can be supposed that is understated a particular happening (for instance, one week ago took place a full day’s testing of the ability to use the machine).

“Tell me of one single thing you did one week ago on the computer.” (meaning “I know well that you did nothing, not a single thing.”)

The translation would be this (the subjunctive is needed);

• Parlez moi de seulement une chose que vous ayez faite sur l’ordinateur il y a une semaine.

B The context of the last sentence is common; it shows no difficulty. Adverbs of emphasis have to be added in order to make up for the oral stress which does not exist in French.

List all of the things you have done within the last week on the computer.

Énumérez précisément toutes les choses que vous avez faites sur l’ordinateur pendant exactement toute la semaine dernière.