在ebay上购物，如何在同一个店家处购买多个商品？

可以使用购物车功能的，Add to Cart，以下是英文介绍，现在忙，来不及给你翻译，不过你应该也看得明白吧。

You'll see a shopping cart icon at the top of most eBay pages. You can add any item that is listed in US dollars to your cart.
The eBay shopping cart lets you keep all of your items in one place and pay for them at the same time.
To remove items you've placed in your cart, click on Remove next to each item. If you don't want to purchase an item in your cart immediately, click on Save for later.
Shipping discounts are automatically applied if the seller has set up discount rules. If they're not, click on Request total from seller.
Fixed price items are available to other buyers until they're paid for, even when they're in your cart.
If you see a message that an item isn't available, it could be because the listing has ended, or you've been outbid and you need to place a higher bid.