This page will show you a few examples of item table configuration for you to get inspiration
tables/item_table1.yml
# Between 1 to 2 unique items will be chosen among the listed itemsamount:1-2items:# 'steel_sword' here is just an identifier. It doesn't represent any actual valuesteel_sword:chance:2amount:1material:IRON_SWORDdisplay-name:"&aSteel Sword"enchantments:unbreaking:2sharpness:1diamonds:chance:2amount:2-5material:DIAMONDgolden_apples:chance:3amount:1-2material:GOLDEN_APPLEkatana:chance:1amount:1# 'mi:' lets RPGChest know it should look for an MMOItem item with the id 'KATAN'item:mi:KATANA# Here is the probability for each item to be chosen, considering their chance value# steel_sword: 2 out of 8 (2 + 2 + 3 + 1) as its chance is 2# diamonds: 2 out of 8# golden_apples: 3 out of 8# katana: 1 out of 8