I definitely suggest multiple tables and using linked records. #1 above would be using Airtable like a spreadsheet, which it is not. #2 above would be using Airtable like a database, which it is. So you will get a lot more out of Airtable if you use it for what it is intended for.
A general piece of advice for working with databases is to create a new table for each new and different “thing” you need to represent in your data. If this “thing” you want to represent has multiple attributes that every instance of that “thing” will have, by virtue of being one of those “things”, then each of those attributes will represent a field (column) in that table. Name your tables the plural version of the “thing” that each record (row) in your table represents.
So, for your case, some examples might be:
Table = {Customers}
each record represents a Customer
Table = {Projects}
each record represents a Project,
and each Project is linked to a Customer,
and a Customer may be linked to more than one Project
Table = {Phases}
each record represents a Phase of a Project,
and each Phase is linked to a Project,
and a Project may be linked to many Phases
Table = {Meetings}
each record represents a scheduled Meeting,
and each Meeting is linked to a Project,
and a Project may be linked to many Meetings
In this way, you create a relational structure with your data that becomes much clearer to follow and easier to maintain than creating tens or hundreds of fields (columns) in a single table.
