Explanation
These are two actions that will improve the performance of the case list views that are slow to load because of the large number of cases in the system. Filtering the views by case owner will limit the number of records returned by the views and make them load faster. Reducing the number of fields displayed will also reduce the amount of data rendered by the views and improve their speed. Verified References: :
https://help.salesforce.com/s/articleView?id=sf.reports_listviews_bestpractices.htm&type=5 :
https://help.salesforce.com/s/articleView?id=sf.reports_listviews_create.htm&type=5

The Lightning Service Console is a user interface that allows you to manage multiple records on one screen and quickly access important information. You can use tabs and subtabs to organize your records and switch between them easily. To meet the requirement of viewing the case history of other cases for the same account when viewing a case, you can use account tabs with case subtabs. This means that you open an account record as a primary tab and then open related cases as subtabs under that account tab. This way, you can see all the cases for that account on one screen and compare their case histories. Verified References: [Tabs and Subtabs in Lightning Console Apps]