You can only delete entries in this list that you have created yourself. Any entries automatically added by Brave for the reasons below can only be removed by disabling/removing the reason they were added in the first place.
Google login button cookies
You can find it under Settings->Social media blocking (or navigate to
brave://settings/socialBlocking) on desktop, or Settings->Brave Shields & Privacy->Social Media Blocking on Android (possibly also on iOS but I won't have access to a test device for a while).
Disable the feature, then you should be able to go back the to list of permanently allowed cookies and the two entries should automatically be gone.
Cookies from Brave Shield settings
If you have dropped your Brave Shields, or set Shields to allow cookies, for any specific sites they will also appear in this list, and cannot be removed.
There may also a bug with Brave Sync that can cause entries in this list to not be deletable, or to return after deletion. [Current August 31 2021 - status unknown at March 29 2022 - have not heard reports of this issue for a long time]