It depends on the data you want to save and how to use them later.
There is a subject in database theory: “database normalization” that could be interesting for you. Shortly - you check what data is similar and split it into smaller entities.
Example: imagine you store user invoices. One table would be like this:
surname, name, email, address, date, value, item, item price, quantity
(bit different on bubble since there are lists, but still…)
in this case you can easily see that lots of data will be repeated (storage space) + possible discrepancies (what if eg, surname or address is once typed wrong) and each time you want to see small info about user - you fetch all data about his invoices (at one stage it will hit performance - depends on the amount of data you gonna deal with)…
After normalization - this translates to few tables:
User
name surname address email
Items
name price
User_order (invoice)
user, value, shipping address, date
Order_items (invoice positions)
invoice, item, qty, price
As you can see - easier to manage, access, update, present… Maybe you could give some examples what you want to store.
Additionally, with bubble - you have data privacy settings. If some data should be visible to only users, other to others - it may be easier to manage with more Things in place.
Now, the performance - theoretically (haven’t tried yet) with bubble you can scale the solution if needed. So ask yourself how often you will need small pieces of data = 1 small query vs big pieces of data = many small queries / one big
Hope that helps.