Keywords - column or separate table I am building a website on  MySQL with php, and I have 400+ products in a table. I have three columns with comma separated values, each has 1-3 values separated by commas in each row.
I was wondering if my db would be faster if I make separate tables for those three columns?
It may or may not be faster, depending on your data distribution and the queries you execute.  What it will be is better.

Normalisation isn't a goal in itself.  It's a series of processes one applies to remove potential errors while changing data.  The output is a schema which is resilient to changing data.  Without normalisation you leave yourself open to inconsistent data.  It really doesn't matter how fast your site runs; if it's wrong it's wrong and it's no less wrong by being wrong quickly.

Separated values could potentially be faster if your current queries retrieve too much information because it is all bundled up together in CSV columns.  It will definitely be faster if, down the line, you discover you have to join to another table on one value currently embedded in a CSV.  At that point your performance will fall off a cliff.