Create a miniature zoo that kids can play with and explore. Gather a wide variety of toy animals, such as lions, zebras and bears. Glue strips of green crepe paper to a large sheet of canvas that covers the table to create fake grass. Consider cutting out some trees out of cardboard and also gluing them to the table. Add the toys around table and give the kids magnifying glasses so they can find and examine each animal. Perhaps make it into a game by giving a point to the child who finds an animal you call out first.
Kids love looking for buried treasure, so take a large cardboard box and fill it with sand. Then, bury some items such as fake gems or gold coins, or perhaps even a take-home toy for the child. Give the kids toy shovels and let them dig through the box for the items. You might even challenge them by buying a small box filled with treasure in one place, and creating a little treasure map to guide them to it. You could also create a miniature landscape in the box with cardboard trees and houses stuck in the sand to serve as reference points for the kids.
Have some fun with food coloring to help the kids learn about colors. For example, you can dye bags of rice in different colors and then combine the colors in new bags at different ratios to see how the colors change. You can also do this by dyeing ice cubes and then allowing them to melt in a bowl together. Ask the kids plenty of questions, such as what color they think would result before you combine the colors.
Another option is to provide kids with a range of different materials they can play with using their hands, such as dough, gelatin desserts, sand and water. Let them play with each substance for a few minutes, and then gather them together and ask them to describe the sensation and how they differ depending on the substance.