These menu options set the Bot's range for the size of the selling amount of the wallet's token holding per trade. The randomness engine in the code will generate a random percentage between the minimum and maximum values.
An example:
A wallet holds 10000 Mellow tokens, and the min/max % settings are 98/100. The randomness engine in the code generates a percentage value of 98.9% for the balance of tokens to be sold for the trade, which is 9890 tokens. The bot then submits a sell order for 9890 tokens.