How can i import up to 100 files into the same spreadsheet from:

Filename1.txt

Freq [Hz] dBSPL Phase [Deg]
20.00 116.25 -101.80
20.56 115.78 -73.43
21.13 115.11 -46.75
21.71 113.43 -10.13
22.32 111.14 11.57
22.94 107.99 12.61
23.58 104.44 -0.59
24.23 103.51 -17.97

Filename2.txt

Freq [Hz] dBSPL Phase [Deg]
20.00 114.85 -87.46
20.56 114.33 -114.88
21.13 113.59 -138.83
21.71 111.82 -170.68
22.32 109.53 169.09
22.94 106.39 154.78
23.58 103.27 138.49
24.23 102.07 127.61

ETC...

when done the final spreadsheet looks like this.

Freq [Hz] Filename1 Filename2 Filename3
20 116.25 114.85 112.32
20.56 115.78 114.33 111.84
21.13 115.11 113.59 111.17
21.71 113.43 111.82 109.62
22.32 111.14 109.53 107.61
22.94 107.99 106.39 105.03
23.58 104.44 103.27 102.69
24.23 103.51 102.07 101.7