May I remove some xdata applications?

My drawing has so many xdata application

("ACAD" "RAK" "HARMONY_HLIB" "ADE" "civil_draft" "civil_line_table" "civil_curve_table" "civil_spiral_table" "SDI_XSECTIONS" "ADCADD_ZZ" "SDSK_PMN" "DCA_FIGURE_XENT" "DCO15" "SDSK_POINT" "SDSK_CVP_1301" "TDNW" "TKKW" "ACAD_DSTYLE_DIMTEXT_FILL" "ACAD_PSEXT" "AcAecLayerStandard" "ACAD_DSTYLE_DIMJAG" "ACAD_DSTYLE_DIMTALN" "ACAD_DSTYLE_DIMEXT_LENGTH" "ACAD_DSTYLE_DIMEXT_ENABLED" "ACAD_DSTYLE_DIMJOGGED_JOGANGLE_SYMBOL" "ACAD_DSTYLE_DIMARC_LENGTH_SYMBOL" "AcadStringInfo" "AcadAnnoPO" "AcadAnnotative" "ACAD_MLEADERVER" "AcMapDMDisplayStyleRegapp" "MapGWS" "AeccLand80" "ACAD_EXEMPT_FROM_CAD_STANDARDS" "AeccUiQTO" "AeccUiQTOEntityPayItemData" "AeccUiQTOPayItemFilePath" "AeccUiQTOPayItemCategoryFilePath" "AeccUiQTOFreqUsedPayItemsList" "AeccUiQTOPayItemFormulaFilePath" "AeccUiQTOPayItemSpecBookVersionFloridaDOT" "AeccUiQTOPayItemFormulaParameters" "AeccUiQTOPayItemFormulaExpression" "AeccUiQTOTransportDesignerFileFloridaDOT" "AeccUiMgr" "AeccUiModel" "AeccLand70" "AcCmTransparency" "AeccLand90" "ACAD_NAV_VCDISPLAY" "AcLayerTools" "ACDBBLOCKREPETAG" "ACAD_DSTYLE_DIM_LINETYPE" "ACAD_DSTYLE_DIMBREAK" "CONTENTBLOCKICON" "ADE_PROJECTION" "HOANHLISP" "ACET-TEXTMASK" "ACAUTHENVIRON" "AcDbDynamicBlockTrueName" "AcDbDynamicBlockGUID" "{1D509D7C-DAFB-45f5-921D-F61E5A28E59C}" "{A63535FC-0515-4076-9DEA-05053D2D0BAE}" "{9F252F4F-F890-4f8c-AA02-C962D59354AF}" "{398DCCB4-48C0-4cd9-AD46-712C62623701}" "KS_TN" "RD_TALUS" "TDT_PAVEMENT" "VNROAD" "TDT_DIEMMIA" "TDT_GHI" "TDT_GEOPOINT" "AcDbAttr" "OffsetDesign" "OffsetDesign_VA" "OffsetDesign_BD" "DiffDgnElev" "AcDbBlockRepBTag" "GradientColor1ACI" "GradientColor2ACI" "AcadAnnotativeDecomposition" "AcadNonAnnoHatchDecomposition")

How can I remove some of it?

I believe you were talking about registred applications. Call the -PURGE command (the command line version, note the hyphen) and use the R options to remove those that were not in use.

To remove data that was attached to entities, please check this previous thread.