Mix the cement powder with water according to manufacturer directions. This can be done in an electric concrete mixer or by hand in a wheelbarrow with a shovel. The concrete should be mixed just before use to prevent hardening prior to pouring.
Place the steel mesh into the base of the prepared tabletop mold to provide support to the bottom of the tabletop.
Mix the cement, following the product instructions, in the mixer just before you are ready to pour the tabletop. Immediately, pour enough of the concrete into the prepared mold to cover the mesh. If necessary, use your fingers (while wearing gloves) to push the concrete into the mesh crevices. Smooth the top of the concrete with the trowel.
Insert the metal rebars into the concrete with four along the sides and two in the center of the mold before pouring in the rest of the mold. Create a smooth surface with a trowel.
Allow the concrete to dry before removing the tabletop mold. It may take up to a week to dry, depending on the depth of the concrete and surrounding conditions.