Hi Jelly. When someone says "let's take a moment for that to sink in." could definitely be interpreted as ' let me take a moment for accepting that'. We usaully use this express as a way to give someone a moment to understand what you have just said.

When you pour water or any liquid onto the ground, you may make a puddle at first. The puddle soon sinks into the soil. That is the image that the idiom evokes. "Take a moment to understand that," or to think about the ramifications of that.

Thanks Courtny and Logan

Yes! You understood well. 'Let that sink in' can mean 'take a moment to accept that.'

Usually people say "let that sink in" after they say something they want you to think deeply about. For example, "About 647,000 Americans die from heart disease each year—that's 1 in every 4 deaths. Let that sink in." (as in, think about that a little bit more)