Donne is the form of the verb donner used with la vendeuse, which is third person singular.
The verb donner means to give. In the present tense:
Because la vendeuse = she, the correct form is donne.
Les vis means the screws. It refers to a specific set of screws that both speaker and listener can identify from the situation.
In a shop context, les vis probably refers to the screws being discussed or bought. So the sentence is not just about any screws in general, but those particular screws.
Here, vis is the noun meaning screw, and it is usually pronounced vee.
So:
Be careful: French spelling can be tricky, and some final consonants are silent. Even though vis ends in s, you usually do not pronounce it here.
In this sentence, the most natural meaning is for the screws, meaning the sachet is intended to hold them.
French pour can have several meanings depending on context, but here the purpose meaning is the best fit:
If French wanted to express because of the screws, it would normally use a different structure.
Yes, it is very normal.
The structure is:
So the pattern is:
subject + object pronoun + verb + noun + prepositional phrase
That is a common French word order. The main thing that may feel unusual to an English speaker is that me comes before the verb.