How to add a player to a table?

You didn't add p to the table

speakers =  {"Awesomespyhacker12"}
banned =  {}

function checkSpeakers(name)
    for i,v in pairs(speakers) do
        if (string.upper(name) == string.upper(v)) then return true end
    end
   return false
end

function banPlayer(banner, victim)
    if (victim ~= banner) then
        victim:Remove()
        banned[victim.Name] = victim.Name
    end
end

function matchPlayer(str)
    local result = nil
    local players = game.Players:GetPlayers()
    for i,v in pairs(game.Players:GetPlayers()) do
 if (string.find(string.lower(v.Name), str) == 1) then
            if (result ~= nil) then return nil end
            result = v
        end
    end
    return result
end

function onChatted(msg, recipient, speaker)
    local source = string.lower(speaker.Name)
    msg = string.lower(msg)
    if (string.find(msg, "ban/") == 1) then 
        for word in msg:gmatch("%w+") do 
            local p = matchPlayer(word)
            if (p ~= nil) then
		table.insert(banned, p.Name) -- table.insert inserts the string value p.Name to the table :D
                banPlayer(speaker, p)
		
            end
        end
    end
end

function onPlayerEntered(newPlayer)
    for i,v in pairs(banned) do
        if (v:lower() == newPlayer.Name:lower()) then
            newPlayer:Remove()
        end
    end
    if checkSpeakers(newPlayer.Name) then
        newPlayer.Chatted:connect(function(msg, recipient) onChatted(msg, recipient, newPlayer) end) 
    end
end
game.Players.PlayerAdded:connect(onPlayerEntered)