Hey @minosiants, you’re absolutely right that 0x3a is 58 in decimal when interpreted directly.
However, since the length field is a VARINT that uses ZigZag encoding, the decoded value would be 29 (= 58 / 2).
You can verify this by hovering over Record #1 and confirming that it contains exactly 29 bytes in it, excluding the length field.
If you’re interested, here’s a previous discussion that goes deeper into parsing VARINT.