DreamWorks Animation first captivated children in movie theaters. Then it branched into TV, piping cartoons based on hits like “Madagascar” and “How to Train Your Dragon” into homes through outlets like Nickelodeon and Netflix. Now DreamWorks has partnered with a technology company, Fuhu, on an even more immediate way to reach itty-bitty eyeballs, a highly coveted audience: a tablet computer for children that the studio will be able to program much like a cable channel. “We could push out a new character moment every day of the year,” said Jim Mainard, head of digital strategy and new business development for DreamWorks. DreamWorks and Fuhu, which makes the popular Nabi line of children’s tablets, plan to introduce the product, called the DreamTab, at the International Consumer Electronics Show, which starts Tuesday in Las Vegas.