Is there documentation regarding how Quicksight charges are reflected in the CUR? I'm trying to match what I'm being charged vs the quick sight Pricing page:

If you already have access to CUR, you can get more information from CUR as well, by simply querying additional columns, for example the description of the relevant line item: line_item_line_item_description

If you can't directly query CUR, while you might not find the information you are looking for in the QuickSight documentation, I suggest checking the bulk pricing API: https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/using-ppslong.html

You can find there information about usage types, their billing, as well as description of different fields. While it's not exactly prviding examples how this information is reflected in either Cost Explorer filters, or CUR tables, you can still get valuable information about usage types and explanation what they mean.

You can download offer files either in JSON or CSV format, and you can get separate ones for each service. For example, to get JSON file with ALL the info about EC2 pricing cost and usage data, you can follow the documentation I linked above, and you would get this from here: https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/AmazonEC2/current/index.json

For QuickSight, for example if you wanted to download this pffer file in CSV, you could just replace the file extension at the end of the link, and replace the service code: https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/AmazonQuickSight/current/index.csv

One example you mentioned QS-Reader-Report-Session - in the offer file you will get more information about i, when you search for it in the usageType column. From what I see, this is usage from Enterprise edition, with description - "Number of emails sent".