Is there a wallet that lets you generate multiple ethereum wallet addresses? I don't like the fact that I only use one address and that everyone can see what I have. Or are there other ways to keep our privacy when making transactions with Ethereum? Is there a EIP to enable multiple addresses from one seed key like bitcoin?
You can have multiple address from the same mnemonic in Ethereum just like with Bitcoin, many wallets support this (Metamask, Cipher, etc.)
Expanding on flygoing's answer. ALL Ethereum wallets that are HD(Hierarchical Deterministic) can generate public addresses for you to use from your private key.
Since you are ambivalent about which address you are talking about, I would assume you mean Public addresses.
The overview is that if you have an HD wallet with a private key, you can use it to generate more public addresses.