No, we don't allow you to assign the same keyword to more than one page.
This is because this could be bad for your SEO - it is called 'keyword cannibalisation'.
The reason it's bad for SEO is because it confuses Google about which page it should show for that keyword.
Google much prefer only one page for a given keyword, when it has two to choose from then you do not rank as high in the results.
Here's an SEO audit where I discuss the issue of cannibalisation and why it's bad for SEO in more detail, have a read!