@phiho Do you mean that in the Galaxy Store -> My apps you want to delete something that is listed there?
If so, be aware that it uses so little memory that you won't notice. Basically just some basic information to allow you to easily jump to it in the store and download it or prove that you have it.
If that is what you want, in the My apps area click the Delete over in the upper right. This will allow you to choose which apps to remove from the My apps list.
