Have you discovered the joy of editable grids? This feature was introduced in December of 2016. Editable grid is a custom control in Microsoft Dynamics 365.
"You can enable editable grids at the entity level to use in the main grid, or at the form level to replace read-only sub-grids (associated grids) with an editable grid." An editable grid is similar to entering data into an Excel spreadsheet and has a number of usability benefits. For instance, users can quickly enter lots of data on different records without needing to open new windows or the editable grid usage can align to business processes that include popping in and out of Microsoft Excel.
Additionally, configuration teams can adjust what a grid looks like based on a set of parameters or data. Editable grids also support business rules and form scripting so you can apply custom business logic according to your organization's requirements.
If you want to learn more about how to work with and configure editable grids you can reference the following article or if you want to see some examples of how editable grids are used this TechNet Article has some interesting use cases.