不要多给： not a single cent more?
In my opinion, the key to strengthening your Chinese is to have confidence in your intuition within the context of Chinese. Not saying you aren't already confident, but more so to apply the following method to approach future confusing sentences.

Break them apart by word:

不 don't
要 want, do
多 more
给 give


You can infer from 不 + 要 = don't want, don't do something

As well as from 多 + 给 = give more

不要 + 多给 = don't give more.

From there, you can understand nuances of the sentence given the context derived from the preceding or proceeding sentence.

Preceding sentence: 你给十两银子 : Talking about giving 10 silver coins...

Then the proceeding 不要多给 probably has something to do with not giving any more of what the preceding sentence was talking about. In this case, coins.



An aside:

I would be careful not to rely on literally translating Chinese text into English expressions, but rather focus on developing intuition within the context of Chinese language; this ability to use the target language to dissect more complex meanings in the target language will strengthen your fluency. It will also develop feelings/connections with the Chinese word itself... so you can feel emotion from the Chinese words/texts... rather than getting that emotion from the English expression you've translated it to.

This is because many Chinese words are simply untranslatable to English given their cultural origins.

For example:


  关系: in traditional Chinese society, you would build up good guanxi by
  giving gifts to people, taking them to dinner, or doing them a favor,
  but you can also use up your guanxi by asking for a favor to be
  repaid.


This concept is pretty foreign to English.

So when thinking about 关系, think about it in Chinese context, and not to translate it to the next best word in English.

Or perhaps 风水. 

The list goes on.