Try this
 
-- Server side
function setBans()
    local bans =  getBans()
    triggerClientEvent(client,"setBans", client, bans)
end
addEvent("outputBans", true)
addEventHandler("outputBans", resourceRoot, setBans)
-- Client side
function setBans(bans)
    if bans then 
        for k, v in ipairs(bans) do
            local row = guiGridListAddRow (stfgrd5)
            local serial = tostring(v.serial) or "N/A"
            local duration = tostring(v.time) or "N/A"
            local ip = tostring(getBanIP(v)) or "N/A"
            local nick = tostring(getBanNick(v)) or "N/A"
            local admin = tostring(getBanAdmin(v)) or "N/A"
            guiGridListSetItemText (stfgrd5, row, 1, serial, false, false)
            guiGridListSetItemText (stfgrd5, row, 2, duration, false, false)
            guiGridListSetItemText (stfgrd5, row, 3, ip, false, false)
            guiGridListSetItemText (stfgrd5, row, 4, name, true, false)
            guiGridListSetItemText (stfgrd5, row, 5, admin, true, false)
        end 
    end
end
addEvent("setBans", true)
addEventHandler("setBans", root, setBans)
function outputBans()
    if (source == stfgrd5) then
        triggerServerEvent("outputBans", resourceRoot)
    end
end
addEventHandler("onClientGUIClick", root, outputBans)