This thick cream-like paste version of Art Clay Silver clay is made for repairs, like filling in cracks and ‘gluing’ broken pieces back together. You also use it to stick unfired pieces together, so you can build up large dimensional shapes by making, drying and finishing each piece individually - when they’re all finished, you use the paste to stick them all together, which creates one solid piece after firing. It is a bit like ceramic slip. The paste can also be used to cover a burnable core, like leaves, paper, and cereals to make a fine silver replica.
If the paste is very thick, use a little water to thin it - only add a drop at a time, and stir slowly.