The Home Store is one of World Bazaar's newer shops (it's actually outside of World Bazaar, facing Adventureland). This is a big place. Before the Home Store opened, this location housed two large shops; the space was combined to make the Home Store.
As the name suggests, you'll find various items for the home: towels, soap, perfumes, even plants and gardening supplies. The difference between this and other "home stores" is that one is done Disney style, with images of Mickey and other Disney characters imprinted on most of the merchandise. Almost all of the items in this store are unique to this shop—won't find them elsewhere in the park.
This is a VERY nice shop, and I suggest you stop by sometime during your visit to Tokyo Disneyland. The fact that it's not inside World Bazaar and its generous floor space means that it's not going to be as crowded as most of the other stores in this area.
Here's an item of trivia strictly for the hard-core Disney-theme-park buff: See those second-story windows? That's part of Club 33.