示例：

type ThreadObj = {foo:string}
type ThreadList = ThreadObj[]; 
type ThreadListList = ThreadList[];

const obj: ThreadObj = {
    foo: '123'
}
const singleDim: ThreadList = [
    obj
]
const multiDim: ThreadListList = [
    singleDim,
    singleDim
]

更多

一步到位：

const allInOneStep: {foo:string}[][] = [
    [
        {
            foo: 'hello'
        },
        {
            foo: 'is it me'
        }
    ],
    [ 
        {
            foo: 'you are looking for'
        }
    ]
]

那不就是：

let arr:ThreadObj[][] = []

对于typescript中的多维数组，可以简单地将变量声明和定义为

let multiArr:(string|number)[][] = [["Ram","Shyam",1,2,3,"Hari"]];