"盛奶油的器皿" can be translated into English as "a container for cream" or "a cream vessel".
"A container for cream" is a more straightforward and commonly used expression, clearly indicating the purpose of the vessel.
"A cream vessel" is a slightly more formal or literary way of saying it, where "vessel" can refer to any kind of container, especially one used for holding liquids.
In most everyday contexts, "a container for cream" would be the most appropriate and easily understood choice.