Rest API Limitation: 75 Tables

Hi,

I don't completely get the limitation of max 75 Tables. What does this limitation refer to?:
1. I can have a total maximum of 75 Tables in all of my datasets I push data into, for example 30 Tables in Dataset 1 and 45 in Dataset 2

2. I can have 75 Tables per dataset I push data into, for example 75 Tables in Dataset 1, 75 Tables in Dataset 2 and so on

Thanks in advance,

David