On variations in deaths by ethnic groups this is useful reference https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/733093/PHOF_Health_Equity_Report.pdf

On this https://www.theguardian.com/world/2020/apr/22/racial-inequality-in-britain-found-a-risk-factor-for-covid-19 hard to know what to conclude given lack of analytic details, model used, lack of uncertainty intervals etc

Pinning down importance of factors explaining variation in covid deaths requires a model of factors - age, occupation, income, underlying health conditions, life style behaviours etc - known or suspected to be relevant. Hard to reach any conclusion w/out such analysis