I'd suggest using a grid-based structure that fits your stack. That way you should be able to implement grouping / filtering functionality to help the user find the information that is relevant for the user's specific task.
Where I work it't not all too common to display grids with more than a few thousand rows and 10+ columns.
What is very important to keep in mind when displaying large sets of data is to make grouping clear for the user so that information is clearly distinguishable. That way it's easier for a user to find the information that he needs to reach his goals.
The main object for a list / grid is to display the data in a way that makes it easy for the user to find what he needs to find using as little processing as possible.
You shouldn't focus on displaying everything on a single page of the grid, but rather limit the user to a the top items that would be relevant for a core-user and then let the users that need further information use whatever functionality you decide to implement to find any further information (like paging, grouping, filtering, searching etc).
Again, the less information you display the more you can put the user's focus on the functionality of the grid. It's important to keep in mind that a human-being only has a limited attention-span and that we easily get confused / distressed. What this means is that if you use a system for the first time and get faced with a grid of 1000 rows each with 10 columns you might not notice that the grid allows you to search for a specific key in the grid and might feel discouraged to finish your assignment of finding "John Doe who lives in Arkansas" - which will give you a horrible experience of the system.
If you instead are presented with a system that shows 10 rows each with 10 columns that all represent relevant information you might find it easier to find that search-button simply due to the fact that you have less information to actively process.
EDIT
It depends on this: Why would you want to display multiple entries on separate rows? Does it hold any significant value of displaying them on different rows? If yes, then I'd suggest displaying them on separate rows.
However, it's difficult to say if it would be as there is no context to what sort of data you are going to display. If we knew more it would make it easier.
Without knowing what information is relevant to show on your grid I'd suggest considering using detail tables or something similar where you can open a more detailed table of a specific row that might display further detailed information.
For instance it might not be relevant for a user to see who booked the room, what company is using it, the policy status etc.
Again, it's difficult to say what is relevant to display and what isn't relevant as the requirements you have for the application might be completely different from what I would want to display on it from my perspective.
