There's no way to find out what is an herb except specifying all their names explicitly. This will of course also work for 3-4. For example: "trade goods/or/item/gromsblood/or/item/plaguebloom/or/item/or/item/mountain silversage/item/ghost mushroom".
Note that this will not reduce the number of pages to be scanned (which is impossible) but it will not list other items in the table.
The "error" you're getting is not really an error but just a notification. The table size is limited to 1000 for performance reason. I guess I could go a bit higher but there has to be some limit. If you're doing a historical scan it doesn't matter and otherwise you just have to use a more strict filter to limit the results.
PS as this forum is going to be closed please post further questions/bugs etc. directly on github