Grid component allows developer to configure Empty state to make empty grid look more appealing for user.
By default, when Grid is empty user sees it as:

Unfortunately, it’s not very engaging, so let’s create Empty state for it! There are a few steps you have to follow:
src/PrestaShopBundle/Resources/views/Admin/Common/Grid/Blocks/EmptyState directory, so Grid component can locate it.supplier then template name must be supplier.html.twig).In Empty state template you can put whatever you want to: an image, some helpful text, a form … but it’s a good practice to describe what data grid displays. See Suppliers grid empty state as an example below.

_default.html.twig template that can be found at src/PrestaShopBundle/Resources/views/Admin/Common/Grid/Blocks/EmptyState.