DAI.e on Avalanche is a token representing DAI on Avalanche that was bridged from the Ethereum blockchain via the Avalanche Bridge.
For example, when sending DAI over the bridge to the Avalanche Network, it will appear as DAI.e once the transaction is completed.
If you don't immediately see the DAI.e after a successful transaction, you may need to add the token to the wallet you are using so it shows your balance of DAI.e
Note that to send DAI.e back, is the same process but in reverse, resulting in DAI.e turning into DAI.
For a more in-depth read on how the Avalanche Bridge works, please read the following articles.