Data limit for rich/long text fields — Salesforce

You can create as many as Long Text Area or Rich Text Area fields on the Object as long as the total length of all the Long Text Area/Rich Text Area fields do not exceed 1638,400 characters (and the max size for each long text area fields is 131072)

The limit does not apply for records the limit applies for the length of fields on the object.

You can test it by yourself

Create a long or rich text field, in the next page, on the Length input, the Salesforce will tell you, like this,

You are currently using 53,768 out of 1,638,400 characters on this object. You have 1,584,632 additional characters to allocate to this field.

53,768 is currently used in this Object,
1,638,400 is the whole limit,
1,584,632 is available for use,

You will see this error, if you crossed the maximum limit of 1,638,400

Minimum required length for this field type exceeds total number of characters available across all Long Text Area and Rich Text Area fields in this object. Available characters: 0