Welcome to the Airtable community!
What type of users are you thinking of having? If you will building your own portal with the REST API, it will not work.
The API is limited to 5 requests per second per base. If you exceed this rate, you will receive a 429 status code and will need to wait 30 seconds before subsequent requests will succeed.
Other methods of accessing Airtable data do not have such strict limits (e.g. base collaborators using the actual user interface, or publicly shared views published on the internet). However, in general Airtable is not designed to scale up to hundreds of simultaneous users. People who use Airtable as a backend for a website usually need to introduce a caching layer.
If you anticipate the users may “boot up” or open the app at similar times, the answer is still no. You need to forward-cache the data to support heavy access hits to your Airtable service.
One approach is to sync your Airtable data to a SQL database (using this service) and build your app to pull from the SQL data instead of the Airtable service.