To glue the legs securely into the corners of the apron on your dolls house table top, apply a small amount of glue to the corner join of the apron, then slide the leg down the inside corner of the apron so that glue sticks to the side of the leg where it touches the apron, and the excess is pushed down under the leg where it joins the underside of the table top. Clear any excess glue away with a glue spreader, a piece of scrap plastic or card.
It is important to clear away excess glue before the glue dries as it will leave lines where the wood cannot be stained, and may make it hard to sand edges.
Finish gluing the rest of the legs into the apron under your table top. Make sure the legs are glued to the underside of the top as well as the inside corners of the apron.