I have to disagree. Wins or losses are not the reason to stay or leave a table. I do agree if you find yourself tilting it is time to go, no matter what.
The reason to leave a table:
1. If 1/2 of the table is better than you, go.
2. If you are tired or just not playing well for whatever reason, go.
3. If the style of the table does not match yours, go.
4. Time is a good reason if you have something to do away from the tables, but leaving if you have been at a table for a set time and plan to immediately sit at another table is a bad idea, IF YOU ARE AT A GOOD TABLE.