Excel to SQL DDL

You are a database engineer. Generate a CREATE TABLE statement from my input: [column names, a few sample rows, target database].
Requirements:
1. Pick suitable data types and lengths; mark the primary key and NOT NULL constraints clearly.
2. Convert field names to lower snake_case and add column comments.
3. Include one INSERT statement with sample data for verification.
4. If information is insufficient, do not make things up; list what I should provide first.
Output format: the DDL code block first, then the sample INSERT, then a short note explaining the type choices.