I'm using rust-analyzer 0.2.654 (latest) on VS Code 1.57.1 (also latest) on Windows 10.
The autocomplete displays all keywords, as shown below:

How can I hide the keywords, displaying only the actual struct members?
You can disable this in the settings UI by navigating to Text Editor > Suggestions > Show Keywords:
Or alternatively disable it via settings.json by including:
"editor.suggest.showKeywords": false,
"[rust]": { ... }. I don't know if there's more granular control. Rust-analyzer is already pretty contextual IMO and typically doesn't suggest irrelevant keywords. I don't know why it suggests them here.