Paradox 5 Table Specifications
The Paradox 5 table format was introduced in Paradox for Windows version 5. Following are the specifications for Paradox 5 tables.

Up to two billion records per file.

File size is limited to two gigabytes.

Up to 255 fields per record.

Record size: Up to 10,800 bytes per record for indexed tables and 32,750 bytes per record for nonindexed tables. When figuring out the size (the number of bytes or characters) of a table, remember that Alpha fields take up their size (for example, an A10 = 10 bytes), numeric field types take up 8 bytes, short number field types take up 2 bytes, money takes up 8, and dates take up 4 bytes.

Memos, BLOBs, and so on take 10 bytes plus however much of the memo is stored in the .DB. For example, M15 takes 25 bytes.

Up to 64 validity checks per table for Paradox for Windows tables.

A primary index can have up to 16 fields.
Tables can have up to 127 secondary indexes.
Block size can be from 1K to 32K in steps of 1K. For example, 1024, 2048, 3072, 4096, 5120...32768.

Paradox 7 and above Table Specifications
The Paradox 7 table format was introduced in Paradox version 7 for Windows 95/NT. The Paradox 7 table format has all the same specifications as the Paradox 5 table format with two additions. Following are the specification additions for the Paradox 7 table format.

Added descending secondary indexes.
Added unique secondary indexes