DBeaver EE supports Keyspaces schema browser, data viewer and CQL queries execution. Also it supports various administrative tools.
Connecting to Keyspaces
AWS Keyspaces uses AWS IAM authentication.
You need specify your IAM credentials and AWS region. There is no some specific endpoint - there is only one cluster per account per AWS region.
Also there is no need to configure SSH or SSL - DBeaver uses default AWS settings to access Keyspace cluster.
Browsing Keyspaces tables
You can browse, view, edit and filter Cassandra tables the same way as with regular (relational) tables.
However, being a distributed key-value database, Keyspaces doesn't support any kind of referential integrity. There are no foreign keys, references, etc.
Note that Cassandra has very advanced (comparing to relational databases) data type system. Each column may be a collection, map or set of values (with very big number of values). In some cases this makes browsing data in the "Grid" mode inconvenient.
CQL Cassandra Query Language is a kind of very simple SQL language dialect.
It supports simple SELECT queries, DDL statements (like CREATE TABLE) and some other.
You can use standard DBeaver SQL editor to execute CQL queries. DBeaver supports Cassandra query execution, results scrolling, data export/import, mock data generation and other features.
Physical ERD (Entity Relation Diagram) doesn't make much sense for Keyspaces as there are no any foreign keys. However you can make you own custom ERD and connect Keyspaces tables with each other using logical associations.